


Personal Space

by MalMuses



Series: Alien Cas [1]
Category: Supernatural
Genre: Alien Castiel (Supernatural), Aliens, Alternate Universe, Alternate Universe - Science Fiction, Alternate Universe - Space, Angst with a Happy Ending, Astronaut Dean, Bakery Shop Owner Gabriel (Supernatural), Castiel (Supernatural)'s True Form, Castiel Has Tentacles, Consentacles, Creature Castiel (Supernatural), Endgame Castiel/Dean Winchester, Established Gabriel/Sam Winchester, Everybody say aww, Fluff, I promise its not as crazy as it sounds, Interspecies Relationship(s), Interspecies Romance, Interspecies Sex, Jack is adorable, Kid Jack Kline, Lawyer Sam Winchester, Love Can Cross the Cosmos, M/M, Mars Exploration AU, More Wholesome Than It Sounds, Non-Verbal Castiel, Sam is a Good Brother, Selectively Mute Castiel (Supernatural), Shy Castiel (Supernatural), Slow Burn, So many references but actually not crack, Tentacle Sex, Tentacles, Way more feelings than you would expect
Language: English
Status: Completed
Published: 2018-11-21
Updated: 2018-11-21
Packaged: 2019-08-26 15:26:38
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 13
Words: 40,795
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16684189
Author URL: https://archiveofourown.org/users/MalMuses/pseuds/MalMuses
Summary: Dean is an astronaut, and he definitely chose the career so that he could help move humanity forward, not just because he didn't want to sit in an office, thank-you-very-much.Becoming the first human to set foot on Mars was never part of his five-year plan, but he loved his job and couldn't say no when the opportunity arose.He had spent plenty of time thinking about what he was risking never seeing again if something went wrong; his brother, brother-in-law, and the adorable kid they were adopting, not to mention his friends, his car, and pie.What he hadn't considered was what, or who, he might find when he actually got there.





	1. Staging

**Author's Note:**

> I have a lot to say about this fic, so strap in if you're ready!
> 
> First of all, this fic wouldn't exist without the utterly amazing [thefriendlypigeon.](http://thefriendlypigeon.tumblr.com/) It can be hit-or-miss, with these kinds of Bang collaborations, how well you will hit it off with the person you are paired with. I can honestly say I struck GOLD with this wonderful artist - not just in terms of talent, but as a person! Working with you on this fic was so much fun! 
> 
> Please, please go checkout thefriendlypigeon's art masterpost [here,](http://thefriendlypigeon.tumblr.com/post/180357148434/personal-space-spn-reversebang-2018-art) and see the original piece they produced which I claimed during Reverse Bang and the additional amazing piece that they did to go with the story.
> 
> My second person to thank is my spectacular friend and beta [andimeantittosting.](https://archiveofourown.org/users/Saylee/pseuds/andimeantittosting) I don't think I would have had the courage to produce this fic as it stands now without your encouragement and enthusiasm! You were there from start to finish, from vague tentacley outline to final misplaced comma. You are the best!
> 
> I also want to give a shoutout to sharkfish, who's fics showed me that tentacles can be cute, too.
> 
> Huge thanks to the mods of the SPN Reverse Bang. This wouldn't exist without them, and they have been awesome throughout the entire experience - best mods ever, in fact!
> 
> I have a few other encouragers, readers and betas to thank: jscribbles, captainbunnicula, Ellen_of_Oz, SOBS and PieDarling. You are my fic family, one and all, and this wouldn't be half as much fun without you :)
> 
> My last-minute banner savior [saltnhalo](https://archiveofourown.org/users/saltnhalo/pseuds/saltnhalo) also deserves some love here.
> 
> Sometimes it takes a village! <3
> 
> Now - on to the fic itself!
> 
> This fic took a ton of in depth research; I hope at least some of it shows. There are also a bunch of references and easter eggs tucked away in here...anyone who finds them all can have a cookie. 
> 
> Please do comment and let me know if you enjoy the fic, find any of the little references, or just want to say hi! I love having discussions with my readers in the comments; it's the best part of posting.
> 
> THANK YOU. For your time to read, and for not judging me for writing the subject matter any more than I judge you for reading it *WINK*
> 
>  
> 
> Love you guys!
> 
> \- Mal <3
> 
> P.S. - Did you know this fic now has [a sequel?](https://archiveofourown.org/works/17718662/chapters/41801075)

_Keys, check. Coffee, check. Personal bag, check._ Dean took one last look around his apartment before sliding his phone into his pocket and stepping outside. He locked the front door, for what should be the last time for six months.

He only made it three steps down the corridor of the complex before he darted back to give the thermostat one last check; no way was he going to pay for six months of air conditioning he wouldn’t be around to feel the benefit of.

Finally satisfied, he made it to the elevator. By the time he reached the first floor, there was a buzzing in his pocket. Carefully juggling his coffee into the crook of his elbow, Dean reached down and pulled out his phone, turning the screen to see the grizzled face of a begrudgingly-smiling older man in a baseball-cap.

“Hey Bobby,” Dean greeted warmly, letting out a hiss as coffee sloshed over the arm of his favorite Henley. “Son of a bitch, that’s hot."

“What, Mars?” Bobby asked, confused.

Dean held the phone between his ear and shoulder, so he could get off the elevator with his bag. “No, dumbass. I spilled some coffee. I’m not on Mars yet.”

“Yeah, I thought you weren’t supposed to launch until tomorrow.”

“That’s right,” Dean confirmed. “Not to mention, we’re speaking on my cell phone.” Dean smirked. “I gave you the number for the software phone I’ll have to use up there, right? The one NASA will redirect?”

“Yeah,” Bobby replied, sounding distrustful. “Don’t expect I’ll use it much though, boy. Don’t want them listening in on everything I have to say.”

Dean rolled his eyes as he moved to the parking lot at the back of the apartment building, fumbling for his car keys. “Alright, crazy old man.”

“Might be crazy and old, but I could still kick your ass, kid.”

“True.” Dean grinned. Bobby was an old family friend, almost a father to Dean, and he’d been instrumental in encouraging Dean to apply for the space program when he finished his engineering degree. Bobby knew Dean had always been one to take on challenges others couldn’t comprehend. Dean was glad he’d gotten to speak to him before he left. “So, what’s up, Bobby?”

“Nothin’ much,” the old man grumbled. “Just wanted to say g’bye I guess, before you become famous and all.”

Dean snorted. “I’m not gonna be famous, Bobby,” he said. Finally seating himself in the front seat of his beloved car, Dean turned his full attention to the phone call. “NASA will be in the news, but no one is gonna remember Dean Winchester. I’m just the engineering schmuck who gets to go up there early, prep the base and set up the samples for the real scientists who’re coming after me.”

“You keep telling yourself that, boy,” Bobby chuckled fondly. “Your name’s all over the news up here in Kansas. Local boy, first man on Mars, all that.” He paused for a moment, before blessing Dean with some of his signature gruff affection. “We’re real proud of you, Dean. Don’t do nothin’ stupid, y’hear? You gotta come back, you still owe me a hundred bucks.”

Dean laughed. “I should’ve known better than to make a bet with you. You won’t even let fifty-five million kilometers get in the way of collecting, huh.”

“Miles, boy. While you’re still on my turf, I want miles.”

“Your turf? I’m in Florida, Bobby. Kansas is a fair way away.” Dean grinned.

“Whole of America is my turf, kid,” Bobby grumbled warmly.

They spent a few more minutes chatting back and forth, and Bobby made Dean promise to call his brother Sam when he could, as if Dean would forget. Goodbyes said, Dean hung up and threw his phone down onto the empty passenger seat of the ’67 Chevy Impala.

Everything was quiet for a minute, and he relaxed, taking it in. _Maybe I’ll get a slice of pie on the way to the Kennedy Center,_ he mused. _I should say goodbye to Gabriel anyway._

 

~~***~~

 

Trick or Sweet bakery was a shockingly bubblegum-pink building in central Merritt Island. Gabriel, Dean’s brother-in-law, had opened it two years earlier when he and Sam had followed Dean across the country. Sam had graduated from law school in California and told Dean in no uncertain terms that “the law works everywhere, but you need to be where NASA wants you.” So, Sam had taken his bar exam and then set himself up as an attorney in the commercial district of Merritt Island. The baker and the lawyer sometimes made an odd couple, but Dean was delighted to have them both close by.

“Dean-o!” Gabriel’s bright voice bounced over the counter as Dean stepped into the small store.

“Hey, Gabe. Didn’t think I’d leave without a last slice of pie, did you?” he said, grinning.

“I would hope not,” the bubbly, blond man replied with a wink, already unfolding a large Trick or Sweet branded box and beginning to fill it with pie slices. “You won’t get food like this on Mars,” he pointed out, in a tone that suggested it was a good reason for Dean not to go, “so it’s on the house.”

“I won’t.” Dean sighed dramatically. “But I also won’t get paid if I stay here,” he pointed out. “How can I be a good uncle to that terror you’re adopting if I can’t spoil him to death?” he added, shrugging helplessly. “No choice but to go to Mars.”

A fond smile rolled across Gabriel’s face, changing his teasing tone instantly. “Sam’s filing more papers at the courthouse today, actually. I’m sorry you’re gonna miss us bringing him home, Dean.”

“You’ll just have to keep him spoiled for me until I get back,” Dean responded with a genuine, wide grin. “It’s just great to see you two finally getting to have this. You’re going to be dads.”

“And you’re going to space,” Gabriel pointed out, bounding around the counter with the overflowing box of pie. Holding it carefully out to the side, he held his arms open for a hug. “That’s pretty exciting too, bro. You’re gonna call, right?”

Dean was at least a foot taller than Gabriel, so their hugs were always a little awkward, but warm. Dean counted himself lucky to have the mischievous baker as a brother-in-law. He gripped him for a moment longer than he usually would, saying goodbye. “Of course I’ll call. How else are we gonna keep Sam in line?”

“Too right,” Gabriel agreed fondly, passing over the box. “You ready to go, then?”

“Yup,” Dean nodded as he tucked his precious pie cargo into his arm. “Heading up to the Kennedy Center now for my final briefings, then lift-off tomorrow. Thanks for the pie, man. It’ll be a great goodbye to Earth.”

“Wow,” Gabriel said seriously. “It’s really happening. Just…” he paused, uncharacteristically somber, “be safe, okay? I saw that movie, with the dude on Mars…”

Dean rolled his eyes. Matt Damon had caused him no end of trouble. “I’ll be fine, Gabriel. NASA has been planning this mission for years. Everything will be exactly how I expect—red, dusty, and a little boring when I get over the view.”

Gabriel grinned again, clapping Dean on the back. “Alright then, Dean-o. Speak to you when you’re on Mars, I guess.”

“Sure will,” Dean threw back over his shoulder, turning to carry his spoils to the car.

Immediately outside the door of the bakery, he had to sidestep quickly to avoid crashing bodily into a tall, dark-haired man in a beige trench coat.

“Sorry!” Dean grinned apologetically. “Could barely see you over my pies,” he lifted the box, still smiling.

The man nodded, and Dean was momentarily struck by his vivid blue eyes. Before the handsome man could respond, a slim blond woman came up behind him, dragging a reluctant-looking young girl by the hand.

“Come on Jimmy, we’re going to be late—” She ushered him on into the shop.

The man, Jimmy, gave Dean a nod as he moved aside to let the woman—his wife, Dean assumed—go first. “Don’t worry about it.” He smiled at Dean, before moving through the door to the bakery after the girl.

 _Why are the cute ones always taken?_ Dean thought idly as he eased open the door of his car. As much as running into an attractive man or woman was always fun, Dean’s life hadn’t really worked out for him to meet anyone. Few people were willing to date someone in such a dangerous profession, who could be away for half a year at a time.

Easing behind the wheel, Dean smiled fondly around at his Impala. He’d miss her, too. He called the black beauty Baby, and she was practically family. He placed the box of pies almost reverently onto her passenger seat.

He devoured a slice of cherry pie before even doing up his seatbelt, it was so good. His brother-in-law sure could cook. Which was amusing, given that Sam was a health freak and rarely touched anything Gabriel made. Though, Dean wasn’t really sure if that was due to the calories or due to the number of pranks and “experiments” Gabriel had put him through over the years.

Musing fondly on his little family, soon to grow bigger in his absence, Dean drove the rest of the way to the Kennedy Space Center.

He was to have his last briefing there before he began the long series of preparations for launch the afternoon of the next day. Dean was nervous. He’d been in space before; his first trip off the surface of the planet after he completed his intensive training and test flights had been two months on board the International Space Station. He’d missed Sam and his family, but he couldn’t say he hadn’t loved every minute. He’d been in space! How cool was that? Mars, however, was—quite literally—uncharted territory. He was to be the very first person to set foot on the red planet, to prepare for the bigger mission that would follow.

Parking in his designated spot on the interior lot, Dean grabbed his bag, pie and empty coffee cup so he could head up into the building.

Hours of technical talk would happen that afternoon, followed by a final session in the low-gravity chamber.

Dean focused on his excitement, pushing away any nervous thoughts about what he might find on Mars.

 

~~***~~

 

“T-3 hours and counting,” the voice echoed in Dean’s ear. “Crew to MILA.”

 _Crew,_ Dean thought. _That’s a bit of a joke, isn’t it—it’s just me._

Regardless, Dean made his way to the Merritt Island Launch Area, known as MILA. (Of course, NASA had an acronym for everything.) He had walked the path to launch many times both in practice and also for his previous missions. This one was going to be longer and more arduous, but the principle was the same.

Not many of NASA’s missions were solo missions. There was safety in numbers. But Dean was an experienced astronaut with a solid engineering background, and it was cheaper to send just one guy to prep for the science team than a whole crew. In the back of Dean's mind, of course, he also thought that it might mean he was just more expendable than the rest of his crewmates.

Pushing morbid thoughts about his expendability out of his mind, Dean settled in and began his cockpit checks.

“Launch Control, this is Ares 1. Do you copy?” Dean began.

“Ares 1, this is Launch Control. We copy,” came the response from the Kennedy Space Center.

“Mission Control, this is Ares 1. Do you copy?” Dean continued his script.

“Ares 1, this is Mission Control. You're clear,” the second answer came from the Johnson Space Center, who would control his mission after launch.

“Launch Control, this is Ares 1. Initial communication check successful.”

“Ares 1, this is Launch Control. Clear to close hatch. Begin checks and close-out.”

“Loud and clear, Launch Control. Beginning checks. Communication will re-establish for close-out and countdown,” Dean confirmed, before initiating the signals to the ground crew that would prompt them to begin the final preparations.

This part was Dean's favorite. NASA ran like a well-oiled machine these days, with hundreds of manned launches under their belt over the years, but there was still always enough tension to give Dean an adrenaline rush. Sam thought he was nuts, but Dean lived for launch day.

Ares 1 was a fascinating rocket, too. Technology had only recently advanced far enough to allow manned trips like this to Mars. Orbiters and robots had been going to the red planet for years, but this was the first time a human would walk there. To get there successfully, the rocket held several stages of fuel. Staging as a tech was old news; fuel was stored and ignited in several chambers that dropped off the rocket in stages as they emptied, reducing the weight of the craft as it climbed. It was tried and tested. But using a second stage of fuel for a return trip was both ingenious and dangerous. There was always a risk, despite every precaution, that the secondary fuel supply would be damaged upon landing. If that happened, either he'd die in a ball of flame or he'd be stuck on Mars.

Perhaps he should have paid more attention to that damn Matt Damon movie after all.

“This is Launch Control. White-room closed out, ground crew proceed to fallback area,” Dean heard after what seemed like an eternity. Things were really moving, now.

He shifted in his suit, getting comfortable, feeling his excitement build. Launch, for Dean, was like the world’s best roller coaster.

“T-20 minutes and hold,” Launch Control announced. This was the last hold before take off. Dean’s test director, a cheerful, nerdy little man named Ed, would give his final briefing, and then they’d start thermal conditioning the fuel cells.

Everything passed super quickly for Dean; he had checks to make and protocol to recite, questions to answer and reports to give. Before he knew it, they had their final launch window.

The flight recorder was activated.

“T-9 minutes and counting.”

“Start auxiliary power units. Arm solid rocket booster safety; arm devices.”

“Ares 1, this is Mission Control. Close and lock visors.”

“This is Launch Control, ground launch sequencer is a go for start. Activate launch pad suppression system.”

Dean gripped hard at his arm rests, leaning back. His heart raced.

“Ares 1, this is Launch Control. You are clear. Main engine start.”

“Ares 1, we have solid rocket booster ignition.”

Dean quaked in anticipation.

“Ares 1 to Launch Control,” Dean whooped. “Liftoff confirmed!”


	2. Rocket

Two months. Dean had two whole months to kill.

The worst part of being an astronaut was definitely the commute. Dean would be on Mars for around eight weeks if everything went to plan, but it would take two months to get there and another two months to return. He’d then spend two weeks in medical observation before he could see anyone or even drive to his apartment.

It wasn’t too bad, in Dean’s opinion, hanging out in Ares 1 for the trip. The craft was programmed down to the last degree, flown more by computers on the ground than by Dean. He had to check on things and send daily reports, but in-transit he had a lot of downtime.

As long as he checked in with NASA during his appointed windows and met his daily exercise requirement, Dean could do as he pleased.

The small craft didn’t have as much entertainment as Ares Base, his destination on Mars, would have, but the computers held a lot of movies and shows, and he even had limited internet access. He had a software phone, so he could speak to family and friends. It wasn’t so bad. Just quiet, mainly.

Nonetheless, Dean looked forward to reaching Ares Base. The compound down on the red planet had been constructed exactingly by robots over the past year. Up until the science team arrived to begin colonization experiments, the construction of Ares Base had been NASA’s biggest project to date. It had high tech science facilities, living space, a breathable atmosphere and increased gravity simulation. The value of G on Mars was only 3.711 m/s2; compared to more than double that on Earth. It wasn’t impossible to walk on the surface, but it was sure going to be bouncy.

Dean had trained for it, of course, but he was excited to see what it was actually like to walk on an alien planet—his missions to the International Space Station hadn’t prepared him for that.

After breaking through Earth's atmosphere and successfully engaging the programmed pilot, Dean was on his own. He was cut off from Launch Control at MILA; his only contact now would be with Mission Control at Johnson Space Center, in Houston, Texas. The NASA director there wasn’t as cheery as Test Director Ed. Naomi was a stiff, somewhat unpleasant woman—given the amount of PR work she had to do, Dean had no idea how she had her job. He wasn’t particularly looking forward to reporting to her for the next six months until he touched back down.

Stretching himself out of his seat, Dean took a gentle spin through the cabin. Grinning, he opened up the panel for the software phone and hit his brother's number.

It always took a minute to connect, but the wait the first time was the most jarring. What if it didn’t work, and he couldn’t talk to _anyone_ except Naomi, for six months?

“Dean!” Sam sounded just as relieved as Dean felt.

“Hey Sammy,” Dean smiled, reaching across to hold on to the edge of the console to keep himself in place and wave at Sam on the little screen. “Promised I’d call.”

“You better call plenty.” Sam glared, but it was fond. “How is everything? Gabe and I watched the launch online.”

“Ahh, my internet entertainment debut!” Dean joked. “Bet you always thought that would be porn, huh, not space flight.”

“Dean,” Sam hissed in protest, though he chuckled anyway. “NASA can hear you.”

“Pretty sure NASA has heard the word porn before, Sam. If not, they better get used to it.” Dean grinned. “I’m on my own for six months, I hope they prepared the entertainment system at Ares Base for that.”

“Eww, gross, Dean,” Sam complained, but he was cut off as a loud chuckle came from the side of the screen.

Gabriel appeared. “Glad you didn’t explode, Dean-o!” he offered with wide grin. “And that my pie didn’t weigh you down too much to fly.”

“I ate _six slices,_ ” Dean complained, though he sounded delighted.

“I thought NASA had you on a special diet,” Sam interjected, pushing Gabriel aside with an elbow.

“Oh, they do. Careful salt consumption because of the muscle cramps I got on ISS,” he reminded them, “but they can pry my pie and coffee from my cold, dead hands.”

“You’ve got coffee up there?” Sam raised a curious eyebrow, leaning toward the screen.

“Yup,” Dean responded proudly. He may not have been the one to invent it, but Dean took a lot of pride in NASA’s advancements. He was personally invested in his job. The fact that Sam said that was because he had nothing else in his life to be personally invested in was beside the point.

“I can’t believe you’re going to be shooting through space, with no control, for two whole months.” Sam shuddered, causing his long hair to flop across his forehead. “Couldn’t get me into space.”

“I don’t think they could fit you through the hatch, sasquatch,” Gabriel butted in, from somewhere out of sight.

Dean laughed, smiling at the impressive bitch-face Sam passed beyond the edges of his vision. Sometimes being on the outside of his brother’s marriage made him a little lonely, but mostly Dean loved to see Sam and Gabe so happy. Maybe opposites really did attract.

They chatted for a good twenty minutes, Dean detailing as much of his mission as he was allowed to divulge, and Sam filling Dean in on his recent court cases and the fact that Gabriel was trialing a new boysenberry pie at the bakery.

Eventually their chatter turned to Jack, the little one Sam and Gabe were adopting.

“It looks like we should have him with us by the time you get to Mars, Dean,” Sam was excitedly explaining. “It’s such a long process, but worth every moment. We thought of doing the surrogate thing, but…” Sam shrugged. “Jack needs us.”

Dean smiled gently, watching his little brother gush about his soon-to-be family.

“What?” Sam asked, squinting at him through the phone screen.

“What, what?” Dean threw back, grinning again.

“You’re getting all soppy-smiley; it looks weird on you,” Sam teased. “You’re supposed to be the carefree, wild one, remember.”

Dean made a dismissive noise. “Sure, I get it. Because I drink too much and drive a cool car. You know I always wanted a family, Sam,” he reminded him, “wanted a partner. But this life…” Dean let go of the console and twisted, so he drifted slowly around in a spin, indicating the button-crowded cabin. “This life is pretty good, you know. I’m lucky. I don’t regret it.”

Sam nodded familiarly. “I know. And hey, you’ll have Jack by the time you get back.”

“Uncle Dean,” Gabriel agreed from behind Sam. “Got a good ring to it.”

Smiling, despite the strange lurch in his heart at the thought that a bachelor Uncle was all he’d ever be, Dean realized they’d been chatting a while.

“I should go. I have to fit in my exercise requirement before I strap myself in to sleep. Launch was kinda tiring.”

“I bet,” Sam agreed. “Well, we have the schedule for when you’re supposed to call. Don’t go space crazy now, being up there on your own for all these months,” he joked.

“I’m looking forward to the peace and quiet.” Dean winked. He raised his hand, waving to them as he signed off. “Night, you guys. Speak to you in a week. Have some good news for me!”

“We’ll try! We love you, Dean!” Sam and Gabe waved, Sam’s face growing larger and filling the screen for a moment as he leaned in to turn it off.

With a muffled click, the screen went black.

Dean was alone in space.

 

~~***~~

 

Hours made days, and with enough of them, a week arrived.

Weeks moved on and turned into a month.

The loneliness started getting to Dean then, but he knew it’d be okay when he got to Ares Base and had things to do. Until then—another movie, two hours of exercise a day, and reports that said everything was fine and nothing had changed.

A month drifted forward into six weeks.

Slowly, Mars grew closer. Dean could pick the planet out of the darkness, finally—first through the monitors of the craft, and then eventually as a dot in the distance beyond his black windows.

Two months was a long time coming, but he got there.

 

~~***~~

 

“Ares 1, this is Mission Control. Do you copy?”

“Mission Control, this is Ares 1. I copy, over,” Dean responded quickly. He’d reached the point where even Naomi’s voice was welcome.

“Final craft data is excellent,” Naomi responded crisply. “Ready for descent.”

“Thank you, Mission Control. I’ll begin landing procedure,” Dean grinned, though Naomi (or the hundreds of other people he had no doubt were listening) couldn’t see his face.

Dean drifted through the cockpit to his pilot seat, securing the visor of his space suit as per protocol. The cabin had a breathable atmosphere, but on ascent and descent you could never be too careful.

Strapping himself in to the chair, he checked the seals on his gloves before he started to press buttons. The whole procedure was so routine to him it was automatic; he’d trained for months on every flick of every switch. He could land this craft in his sleep.

Dean was terrified.

If anything was going to go wrong, all the odds said it would happen during lift-off or landing. If he survived those, then the likelihood was that he was going home.

Adding to the tightness in Dean’s chest this time was the fact that no person in human history had done what he was about to do. Oh, and they were televising his landing using the exterior cameras with a live audio feed, so he’d been asked to lay off the cussing. Fucking great.

Gripping the chair arm tight with one hand, he depressed his comms button.

“Mission Control, this is Ares 1,” Dean began. “Do you copy?”

“Ares 1, this is Mission Control,” came Naomi’s calm reply. “We copy.”

“You’re very clear, Houston.” Dean smiled to reassure himself, though no one could see. “It’s good to hear some voices.” _Even yours,_ he thought.

“Quite, I’m sure,” Naomi responded formally. “Your data is looking good to us. Stand by.”

The waiting was agonizing.

“Ares 1, this is Mission Control. Hold over—give us your final readings.”

Dean’s chest fluttered slightly with relief. “Mission Control, this is Ares 1. Gotta love waiting through those holds.” He grinned to himself. “Reading 1330, 1069, 15.”

“Sounds good, Ares 1. Begin landing procedure. Keep us updated,” Naomi’s voice paused for just a second, the most emotion he’d ever heard from the somber woman, “and good luck, Dean.”

Dean began the key sequence, the brightly illuminated screens beneath his hands coming to life. “Thank you, Naomi. Landing procedure active. Let's get to Mars, guys.”

The procedure wasn’t too complex, for Dean. After all, Ares 1 took care of most of it. He pressed buttons at appropriate times and updated Houston periodically as the process unfolded. Once he’d reached the final stages, Dean leaned back into his seat, listening to Naomi count him down.

“Landing systems successfully engaged. Begin descent.”

Dean’s fingers crunched into the chair, his head pressed back into the headrest. When the descent began, the g-force would do that for him, making him unable to lift his head off the chair or barely move even a finger until the landing was complete, but fear gave him a head start on the motion.

“I copy, Mission Control. Ares 1 beginning descent.”

The final checks of those precious numbers that told him how the spacecraft was aligned to the planet below, the final few positive pings from the computer, the final switches, the final buttons.

When the g-force hit, Dean could do nothing but watch the screens, the pressure keeping him prisoner.

As the red planet raced up to meet him, Dean threw out a prayer to a God he had no faith in. If he needed a guardian angel at any point in his life, it was now.


	3. Shooting Star

He was alive.

It was the only thought that he had room for, whooping through his comms microphone as Houston and all the observers around the world cheered with him.

Dean Winchester was on Mars. A human, on Mars.

It took many hours to go through the seemingly endless strings of protocol before Dean could even leave Ares 1. He’d landed exactly where he was supposed to, less than a mile from Ares Base. In the hold of the new-tech rocket that propelled him here, there was a contraption that looked like an advanced dune bike. It was to be his vehicle while he was here. She was no Impala, but Dean thought they might have fun regardless.

Once cleared to do so, Dean entered the hold and revved her up. She was noisy, but he was excited to ride her across to Ares Base.

“Come on, Siona,” he said to himself, glad he didn’t have to admit to anyone that he’d nicknamed the bike after his favorite character from _Dune._ “Let’s get going to our new home for the next eight weeks.”

He wasn’t particularly concerned about talking to himself; he had to have someone to listen to.

Initiating the spacewalk feature on his suit, Dean straddled the seat of the bike. She was built like a motorcycle, so Dean could lean forward to steer, but with an outer frame in case she rolled in the Martian dunes, and much more expensive tech than your average Harley.

When space exploration had first begun, astronauts hadn’t had much reach, having to be tethered to their vessel. Dean was grateful, given the scope of the mission, that things had come so very far; as long as Dean’s suit was fully charged, he’d be able to walk out in the alien environment for hours before he’d have to turn back.

He keyed in the sequence to begin the air lock adjustment to his new environment.

Dean practically throbbed with excitement as the door to a new world opened.

Everything was a dull red and dusty as hell. _No wonder they sent me on that four-week Sahara training,_ Dean mused.

Mars was both exactly like all the simulations and nothing like them at all. They’d gotten the dust right, the strange chill in the air that he felt even through his climate-controlled suit, the slightly odd weightlessness that half-gravity produced. But they couldn’t truly account for the view, not even with live video feeds or advanced green screens.

Mars was breathtakingly beautiful, in the most alien way Dean had ever seen. After moving Siona down onto the red sand, he simply had to stop for a moment to stand next to her, one hand on the bike frame, and ease his feet down onto the ground. He stood, taking everything in.

The dunes and vistas that occupied most of his view seemed to go on forever, the sand undulating before his eyes in the constant wind. Where Ares Base had been built, the winds weren’t as bad as nearer the poles. Nonetheless, he expected ferocious dust storms and vicious gusts periodically, even if NASA had spent thousands of computer-hours calculating the exact best time for him to land, weather-wise.

Beyond the hills and valleys of sand, the entire universe stretched out. Cloud cover was nothing like it was on Earth; a few wisps, so high in the atmosphere Dean’s naked eyes could hardly make them out. The lack of thick clouds gave a practically unobstructed view out into the solar system; the same stars and planets that Dean could see from Earth, and yet so very different from here.

It hadn’t rained on Mars for millennia, causing the dust clouds that hung in the thin air. Everything around Dean looked like sunset, reds and oranges against yet more reds and oranges. The darkness beyond, space, just space, only highlighted how alien the red landscape felt.

Across the horizon, a blazing white dot flew diagonally down to a distant part of the planet. A shooting star; a Martian shooting star, no less. Feeling poetic, Dean stopped to make a wish. He wouldn’t speak it aloud, not even here.

After a few minutes, almost reluctantly, Dean climbed back on to his dune bike to head toward the low, grey building in the distance: Ares Base.

It looked like a series of ugly tents from this far away, but Dean knew that within the dust shields which gave it that appearance was an incredibly high-tech facility, which he was here to perfect. Even as advanced as they were, robots could only do so much. Ares Base needed a real engineer, NASA had told him when he received his very first briefing.

“Alright, Siona.” Dean patted the vehicle’s frame once more. “Let’s get this show on the road.”

 

~~***~~

 

 

When Dean first woke up, he had a moment where he couldn’t remember where he was. The bed he was in was comfortable enough, but something felt off. The air felt oddly sterile and the comforter wasn’t his.

 _Oh. Mars,_ Dean thought sleepily, shortly followed with, _Oh shit! I’m on Mars!_

He eagerly swept out of his dormitory-style bed to begin the day. The other three beds in this room were, of course, still unoccupied, so Dean had his stuff spread out over them—not that he’d been able to bring much, of course. Just a few sentimental items.

He’d spent the rest of the previous day running checks on the life support systems of Ares Base before he initiated air and gravity, and finally removed his helmet. The base was self-contained, and within it, there was barely a difference between here and Earth. There was an observation room that looked out over a wide, red ravine—in there, it was fairly easy to tell where he was, but most of the other spaces in the station were windowless. Other than the overly-clean, unscented air, he could walk around just as he would in the lab back home.

Before he’d slept, he’d reported in to Houston, sending Naomi and the rest of Mission Control all the readings from Ares Base and letting them know he’d made it safely and the most important systems were operational.

While Naomi hadn’t exactly managed to sound happy, she did congratulate him, and the voices in the background cheered and clapped. He’d landed, he’d made it to base, and he was going to survive. It was good news for Dean on a personal level, of course, but also wonderful news to the people who ran the budgets for NASA. Dean wasn’t precisely kidding when he joked with Sam that, on a particular level, he was the expendable piece.

He made his way to the kitchen area of the base, known as the galley in NASA-speak, which had been stocked by robotic supply runs long before his arrival. Astronaut food had progressed far beyond everything being grey, freeze-dried lumps, but he already missed Gabriel’s pastries. Breakfast, such as it was, needed to happen before he could start work for the day; not only did NASA regulate his eating patterns in space, for purposes of supply levels and optimum health, but Dean was just the kind of person that could think better on a full stomach.

Twenty minutes later, Dean checked in with Naomi.

“Mission Control, this is Ares Base. Do you copy?”

“This is Mission Control. Loud and clear, Ares Base. Good morning,” A deep, male voice with a Louisiana twang answered the comm. It sounded eerily familiar to Dean.

“Hey,” Dean called through the comms system, abandoning protocol for a moment. “Benny? Is that you?”

“Dean!” came the delightfully southern-accented response. “It’s been a long time, brother. Didn’t know if you’d recognize my voice,” Benny confessed.

Dean and Benny had applied to the space program at the same time and had bunked together while going through their initial training. Benny had headed off for a deep study into interstellar radio waves and Dean moved on up to flight school, and they’d lost touch.

“Of course I remember you,” Dean scoffed. “You were all that got me through those first months of the program. You and your cooking.” He grinned, shaking his head at the coincidence. “You’re working for Naomi now? Where’s she at?”

“I mentioned to Director Naomi that I knew you from back when,” Benny drawled. “She sat down with the other big-wigs and they decided that due to the longer-term nature of your mission, and the isolation and all that, it’d do you good to have a friendly voice on comms.”

“Hell yeah,” Dean replied, delighted. “So, I get you all the time? Naomi ditched me?”

“I’m sure you’ll still get the director sometimes; I still have other work too. And I need bathroom breaks. But otherwise, yup,” Benny confirmed. “You got me, brother.”

Dean and Benny chatted back and forth over the comms system for a few minutes, catching up on each other’s lives, before they knew they should get back on task. Checking the odd-looking digital clock on the wall, showing several different times, Dean sighed.

“I should probably go, Benny,” Dean said regretfully. “My schedule is fairly flexible while I’m here to accommodate what the base needs, but I should get my first surface walk in today; I need some ground dust samples.”

“Loud and clear. Just report to us time out when you begin the walk, you know the procedure.”

“Sure do, buddy. Over.”

Dean headed to the changing room where the space suits were to be kept and charged. For now, his suit from Ares 1 stood in its charging dock. There were boxes here that needed to be unpacked, which contained other suits that had been delivered during the initial supply drops, but for now, Dean would continue to use his suit from his arrival.

Easing his feet down into the heavy boots, Dean pulled the suit up over his legs and waist. He was in an incredibly good mood—so far, his mission had gone without a single hitch, and he was even going to get to chat with an old friend rather than the protocol-stringent Naomi.

Dean unpacked one of the boxes in the changing room to find the sampling cases. There were several ready to go; metal briefcase-style cases with foam inserts holding tools for taking samples and clear vials and bags for holding them. He shouldn’t need anything bigger this time; he planned for this to be a test walk, more than anything.

Moving toward the airlock, he initiated communication once more. “Mission Control, this is Ares Base. Do you copy?”

“Got you loud and clear, Dean. Checking out?” Benny asked.

“Yessir. I’m at 9:06 Mars Time. Not a bad start for my first Sol here,” Dean joked.

A day on Mars, referred to as a _Sol_ , was just a fraction longer than a day on Earth – 24 hours, 39 minutes and 22.663 seconds, to be exact. It was just enough off from Earth time that although it didn’t mess with Dean’s sleep cycles, it meant they had to keep two different clocks.

“9:21 Earth Time. You never were a morning person,” Benny agreed. “Stay safe brother. Check in immediately on return. Hit the emergency comms if you need anything until then.”

“You got it. Exiting Ares Base. Over,” Dean responded, before he hit the button to open the final airlock door and stepped out onto the alien planet.

 

~~***~~

 

When Dean had been stationed on the International Space Station, exterior maintenance had been his favorite task, as it was simple as far as the engineering went and required space walking. He’d loved the feeling of weightlessness: like he was suspended in water, but without any sensation of pressure on his skin. Just floating.

Walking on Mars was different but had a familiar lightness to it. He could essentially walk as normal; the gravity was about half that of Earth’s, but it still gave an odd weightless sensation and a split second during every step where both feet were off the ground if he went too fast.

The red dust made soft crunching and crumbling noises underfoot as he moved his way out of Ares Base, walking slowly to adjust his gait to the atmosphere and the weight and mass of the space suit. It didn’t matter how long he spent in simulation chambers; it was never exactly the same.

Less than a hundred yards out from the airlock, Dean paused to look around. Scientifically speaking he was surveying the world around him, looking for good sites to take samples, interesting formations that he may want to map for the scientists that would come later, looking for anything odd or unusual. But just as much, he was simply admiring the view and taking a moment to truly appreciate being here.

He was on Mars.

Alone.

Fuck.

It was awe inspiring, but low-level terrifying if he thought about it too much. The wide-open cosmos above him, stars visible even during the day due to the lack of cloud cover, spread on for a literal eternity. It was mind blowing, even to someone who’d studied the concepts.

Standing in the dull crimson sand, Dean felt very small. The curve of the planet was a lesser angle than on Earth, and his vision seemed to stretch on much further than back home. The planet was so eerily empty, it made him oddly emotional.

Shaking his head, Dean began to make his way over to where he’d left Siona the dune bike. The feeling of riding her over the low, undulating hills was one he was going to become very fond of, he realized, despite the wind that constantly whipped around him.

His monitors told him he’d travelled about three kilometers, to the first flagged test-site that NASA’s robotic missions had indicated would be a good area for sampling, before anything seemed off. But when he got off the bike, something felt… different.

He couldn’t put a finger on it or make any sense of it, but something was making the hair on the back of his neck stand on end. Looking around and seeing nothing, he shook off the weird sensation as related to the struggle through the wind and the unerring sensation of _differentness_ that plagued everything here. He bent down near the flag, beginning to take measurements to create a grid on the ground to map his samples.

He worked for at least half a Martian hour, his movements slowed by his thick gloves and the fact he wasn’t yet adjusted to the lower G. He could move more easily than he was used to on Earth, and it was easy to stumble or make a movement too sharply, too hard, which could actually send him flying.

He was already tiring, between the odd gravity, suit and weather, but he was so focused that he didn’t register when the strange feeling initially returned; when he noticed it, he realized that he’d already been feeling it for a few minutes.

He straightened, looking up curiously… and almost jumped out of his skin when there was movement out of the corner of his eye.

Not dust-floating, sand-tumbling, rock-rolling movement. Something moving with intent, in his direction.

Holding his sample case in one hand, Dean raised the other to shield his visor. The sun wasn’t quite as strong here as he was used to on Earth, but it could still cause a glare. Glare, however, was definitely not responsible for what he saw.

There was a _person_ walking in the distance.

Dean couldn’t make out much; the person seemed to be wearing a long overcoat with something dark underneath. He thought it was a man with dark hair, but from far away he couldn’t be sure.

They were steadily moving toward him.

A sense of panic clenched at Dean’s stomach, bile instantly rising into his throat. How could someone be walking around up here without a spacesuit? How could someone be walking around up here _at all_?

Dean squeezed his eyes shut tight and shook his head, a little more sharply than he’d intended given the low gravity.

 _Okay Dean,_ he thought firmly. _You’re imagining things. Hallucinating. Maybe you’re low on oxygen, or something is contaminating your suit..._

When he opened his eyes and peered forward again, he was still there, and getting much closer. It was definitely a he. Dean could make out the dark hair now, and the open tan trench coat that whipped around him in the wind.

 _He looks like a freakin’ tax accountant or something,_ Dean considered, his disbelievingly wide eyes locked on the man’s suit and sensible shoes. He was wearing a tie, too; dark blue and whipping wildly in the Martian weather.

 

Again, Dean slammed his eyes shut in panic; again, the man was still there. Coming closer.

 _What the fuck,_ Dean freaked out mentally, grabbing his sample case in one hand. He was frozen, not sure whether to approach the bike, or run, or try to greet the man. _He has no protective suit. Son of a bitch, what the fuck is this? What’s happening?_

Dean’s mouth was suddenly dry. When he made the decision to move toward the dune bike, his feet struggled to cooperate. Fear had him rooted to the spot.

The dude was staring at him as he approached. Just staring. He was much closer now, and Dean could make out his features. The man was incredibly handsome; in any other situation, Dean would have been marveling at how hot this dude was. His dark hair was whipping in the wind, messy and soft-looking. He had thick lips and a sprinkling of stubble across a gentle tan. His eyes—Dean could have sworn he’d seen them somewhere before. So blue. Like an Earth sky right before nightfall.

The staring continued until the man was right in front of Dean. He stopped, very close. A lot closer than Dean was happy with.

He didn’t offer any greeting, didn’t smile.

He squinted a bit, though.

 _Gotta be a hallucination,_ Dean decided, trying to calm his racing thoughts. _Something is wrong with the suit; I’m low on oxygen, or I’m overheating, and this is a mirage._

Ignoring that he was breathing fine and that he wasn’t warm in the slightest, Dean clung on to his theory. Steeling himself, he raised one gloved hand.

The man looked down slightly, directing his gaze almost curiously at Dean’s hand.

Dean poked him in the chest.

He was firm. Solid, real, definitely-not-a-hallucination firm. _Fuck._

The man blinked at being poked.

Dean wasn’t sure what reaction he expected, but the guy just looked very confused. His brow furrowed, and he continued to regard Dean without a word. He made no effort to communicate at all, actually, and simply flicked his gaze up and down Dean from head to toe.

Once more, not quite wanting to let go of the hope this wasn’t real, Dean gave him a poke in the chest.

The man still didn’t make a sound, but the frown that gathered between his eyebrows was definitely displeased.

 _Shit,_ Dean thought. _He’s not a figment of my imagination, unless my imagination just got a hell of a lot better._

The dude moved then. Dean froze as he was slowly circled by the man, who looked him up and down like he was examining something new and interesting, but ultimately beneath him. He regarded Dean rather like one would look at a pretty weed. Something curious, interesting to look at, but ultimately a pest.

Dean’s heart rate was causing the monitors in his suit to beep. It occurred to Dean, deep in the back of his mind, in some lobe that was currently not engaging very well, that he should hit his emergency comms button. It wasn’t instant, it’d have to relay back to Ares Base, but—

Dean’s thoughts ground to a halt as the man in front of him raised a hand, very slowly, to right in front of the visor of Dean’s space suit. The wind was picking up, buffeting Dean slightly, yet despite his flapping trench coat and wild tie, the unprotected walker was totally immobile. It was as if the wind didn’t affect him bodily at all. Dimly, in the back of his mind, Dean thought that must mean he was either incredibly heavy and dense, or incredibly strong. Either way, if he was human, he should be struggling like Dean. He wasn’t.

The hand in front of Dean extended a finger. One nail tapped sharply on the visor. It was accompanied by a scrunched-up, squinty expression of curiosity that Dean would have found adorable if he wasn’t so fucking terrified.

Frowning slightly himself now, Dean raised his own hand again. He poked back at the man’s chest again, harder this time, enough to cause Dean’s own body to drift just slightly back from him. Something about this man was eerily familiar, still. He couldn’t shake it. He jabbed him again, fascinated that he seemed, despite all logic, to be solid and very real.

The man frowned deeply at the jabbing, looking quite angry. With a swipe of his arm, he knocked Dean’s hand away.

The hit wasn’t particularly hard, but unexpected sharp movements had bigger-than-intended effects in low gravity. Smacked with a moderate force by the discouraging hand, Dean flew suddenly back, drifting through the air, down and backwards, until his butt hit the ground. He bounced immediately back up a couple of feet, like a ping-pong ball.

With Dean’s years of NASA training, he knew exactly how to correct himself before it got out of hand. Nonetheless, he panicked. Scrambling, his limbs flapped up clouds of dust as he turned, moving swiftly back toward the dune bike.

He abandoned his sample case, running across the sand in giant, bouncing, low-G strides until he reached Siona. He gathered his wits long enough to climb onto the bike-like seat without ricocheting off anything, and hastily started her engine.

Dean looked back. The man was staring after him, his head tilted slightly to one side as Dean began his escape.

 _What the fuck,_ Dean’s thoughts raced. _He can’t be human. Not out there, in the weather and the radiation, with no suit, too strong to be moved even by these winds… fuck._

_FUCK._

_I just got slapped onto my ass by an alien who looks like an accountant._


	4. Alien

Dean had made it almost a mile on the dune bike before he realized that the man—the _creature_ —was following him. His line of sight was unobstructed, and Dean could see the flapping trench coat moving steadily across the dunes in his direction, following the tracks that his wheels left in the red dust.

Even from such a distance, Dean just knew that the creature was still staring. He also appeared to have something in his hand now, though Dean was too far to make out what. Instead of wasting more time looking, Dean pushed Siona a little harder and raced across the sand, straight back to Ares Base.

He could still feel the back of his neck tingle as _it_ followed.

He tore straight up to the airlock of the grey-tented base, ignoring protocol that would have him park the bike a little further away. With no one else around to impress, it was easy to admit that he was terrified.

Stumbling in through the first door, Dean initiated the pressure change. His hand still on the keypad, he bent over forward, breathing heavily.

By the time the airlock had sealed behind him safely, Dean began to feel a little calmer. He looked back out of the circular porthole in the door. He couldn’t see anything or anyone.

_Maybe he really was a hallucination,_ Dean considered, frowning to himself.

Somewhat reluctantly, unsure of himself, Dean tapped on the airlock comms screen.

“Mission Control, this is Ares Base. Do you copy?”

“Ares Base, this is Mission Control. That was quick, brother,” Benny drawled warmly. “Everything okay?”

Dean paused, biting his lower lip as he eased his helmet all the way off. He exhaled thoughtfully, tucking it under his arm, and shook his head. The last thing he needed was his colleagues thinking that space was driving him nuts.

_But what if it is driving me nuts?_ A little voice in the back of his head poked. _You’re seeing imaginary aliens that look like they sell insurance._

“Ares Base, do you copy?” Benny prompted. “Dean?”

“I copy, Mission Control,” Dean reassured. “Just got tired out quickly when the wind picked up,” he lied easily, though there was an element of truth to it. “Didn’t want to overexert myself on my first sol, over.”

“Gotcha,” Benny drawled. “Time back in?”

“10:12, Mars time,” Dean confirmed.

“10:28, Earth time,” Benny responded. “Alright buddy, thanks for checking in. We’ll expect your daily report at 21:00, Mars Time. Over.”

“Thanks, Mission Control. Ares Base out.”

Dean pressed the button to end the transmission and walked on through the pressurized, oxygenated airlock. He passed through the second door and into the main base, returning to the changing room to get out of his suit.

He sat for a moment once the suit was charging, in his NASA issue grey sweatpants and soft matching hoodie, his head in his hands.

Although his heart rate had calmed, he was still incredibly unnerved.

He was considering going to see how much coffee the supply runs had provided and if he could have another cup, when he heard the noise.

It was a familiar clicking, then some loud thumps and a whooshing sound.

Dean’s blood instantly chilled. Someone had initiated the airlock. He didn’t have to look to know that it was the trench-coated creature—who else could it possibly be? In barely a second, his heartbeat was way back up again. At least he was out of the suit, so he didn’t have to listen to the incessant alarms and beeping that his petrified physical state created. 

He clenched his fists, feeling the sweat that had almost instantly appeared on his palms. At least this time he could think a little more clearly. He had three minutes until the airlock allowed whatever was in it into the base.

He couldn’t override the airlock without endangering the integrity of the entrance hatch, so instead, he took the three minutes to run from the changing room further into the base. In socked feet, he skidded around, looking frantically for a weapon. Anything.

Technically, Dean knew there would be guns locked up in the lab and offices. Weapons had been delivered during the robot runs, as a ‘just-in-case’, standard procedure. They were carefully monitored. Bullets travelled much faster on Mars than they did on Earth, and even the most minor injuries could be deadly here.

Having not had time yet to fully familiarize himself with the layout of the lab, or the presence of mind to be able to locate the key, Dean ran instead to the first room he came to: the galley. Scrambling through unfamiliar drawers and cupboards, Dean managed to locate a knife. It wasn’t a very impressive knife—a small steak knife—but better than nothing. He gulped as he heard the internal airlock door open.

With a hiss and a click, whatever it was that had followed him entered.

Dean briefly considered running to the comms panel, but he couldn’t see what good NASA could do at that exact moment if he gave them the news that there was an alien on Mars—an alien inside Ares Base, for that matter.

He heard steady footfalls. Clutching his knife, he made his way out into the corridor, his heart hammering wildly.

Around twenty feet away, at the turn in the corridor that led to the airlock, was the alien.

Dean planted his feet, realizing that he was shaking and needed all the support he could get.

The man continued walking toward him. His hair was a wild mess—from the wind, Dean assumed. Now that the trench coat wasn’t whipping around him, Dean could tell that he was slim but tightly muscled beneath the suit. Dean readjusted his grip on the knife, holding it ready at his side.  

The man walked steadily down the corridor toward him, regarding him placidly.

Dean felt sweat trickle down his back as the creature came to a halt a few feet away. It was then that Dean noticed that the man was carrying his sample case—the one he’d abandoned in the dust when he’d fled the flagged test site.

Very slowly, as if trying not to spook Dean, the creature stopped and held it up, and offered it out to him. He didn’t speak, but the expression in his eyes was perfectly clear: _You forgot this._

For a second, neither of them moved. They just stared at each other, Dean’s forest green eyes locked solidly on the incredibly vivid, otherworldly blue. Hesitant, sliding forward one foot at a time and still brandishing his steak knife, Dean crept across the space between them, his empty hand carefully extended.

The man didn’t move at all, just held out the sample case for Dean to take.

Slowly, Dean’s fingers eased around the corner of it, stretched forward ridiculously far so as not to stand anywhere near the alien. As soon as he could grasp it he snatched it, pulling it into his chest.

The man didn’t seem offended by the action, watching mildly as Dean bent to drop the case next to his feet. They didn’t break eye contact. Blinking calmly, the creature regarded him. He looked curious, Dean decided, rather than aggressive.

Knowing that he could do little if an alien species attacked him anyway, Dean decided to play along as best he could. Holding up both his hands, Dean spread the empty one in a gesture of placation while he very slowly crouched down to drop the knife on the floor next to the case, showing it to the man. Their eye contact held. When both of Dean’s hands were empty, he showed them to the alien.

Moving his eyes from Dean’s face finally, the creature looked from one palm to the next, taking in Dean’s surrendering of his weapon. He seemed to understand. He gestured to his own front, sweeping his hands down in an all-encompassing gesture, before holding his own hands up, empty, as if to say, _Nothing on me either._

They stood facing each other then, still a few feet apart, hands held up. Slowly, very, very slowly, Dean began to reach forward with one hand. He just wanted to check, just once more, to make sure he wasn’t going crazy out here alone. He balanced on his toes, one leg forward, as the rest of his body still seemed to want to flee in the other direction.

The man squinted at him, furrowing his brow, but eased forward slightly. He leaned in to Dean’s very careful touch of his trench coat arm, pushing back against Dean’s two fingers as if to show him how solid he was. The man gave a small nod as Dean cautiously poked him. _He understands what I’m doing now,_ Dean realized. _He… wants me to be reassured that he’s real?_ It was a strange thought, but given his strange day, Dean allowed it.

Dean gave the guy a cautious smile. _If he wanted to hurt me, he’d probably have done it already,_ he reasoned. _He just didn’t like being poked, before._

“Hello?” Dean offered tentatively.

The man tilted his head but offered no response.

“Do you speak English?” Dean tried again. His hand had confirmed that the man was solid, warm and pretty human feeling. But some kind of sound would be awesome.

Nothing. The creature certainly heard him, his expressions reacted exactly how a human would. He gave a tiny smile even, looking almost apologetic. But not a word, in any language. Silence.

“Okay…” Dean said slowly. He moved his hand, tapping his own chest. “I’m Dean,” he tried. “Dean,” he repeated, slower.

The squint grew more intense for a second, then the curious alien’s expression widened and filled with understanding. But again, not a word.

“Thank you,” Dean spoke clearly, gesturing down to the sample case. “I didn’t stop to get it because—” he gave a cautious chuckle, “well, you scared the shit out of me.”

The man finally moved his hand from where he’d been holding it palm-forward, the universal symbol for appearing non-threatening, it seemed. Gingerly, he reached across the space between them. His hand hovered just above the skin of Dean’s cheekbone. A flicker of uncertainty passed his eyes before he lowered the pads of two fingers to Dean’s face.

Dean held very still.

After softly poking at Dean’s cheekbone, the hand rose to cautiously pet at Dean’s hair. The alien’s head was at an angle, looking intently at his own hand as it gently studied Dean. After a few minutes, for most of which Dean wasn’t convinced his heart was beating at all, the man withdrew his hand.

With another almost imperceptible smile, the creature’s arm dropped back to his side. With that, he stared deeply at Dean for a moment more—a deep, magnetic stare that made Dean uncomfortable somewhere down inside—before he turned on his heel and began to move back up the corridor.

Without turning back to look at Dean at all, the man retraced his steps back to the airlock. Dean heard it hiss and engage, and then three minutes later the outer door thumped open and then closed.

As swiftly and silently as he had come, he was gone. 

 

~~***~~

 

It took a couple of hours for Dean to stop looking over his shoulder, even though he knew he’d hear the airlock again if he had any more unexpected visitors.

On autopilot, he unpacked the samples he had managed to take and took them to the lab. He moved around the base methodically, unpacking some of the boxes that had been left filled by the robots when they dropped off supplies. Robots weren’t good at everything, and apparently unpacking expensive equipment and organizing it wasn’t one of their strengths.

To keep himself distracted, he tidied all the boxes in the lab, unpacked the space suits, moved items in the galley to spots where he could find them while he cooked. When his muscles grew tired, he went and fixed himself up some food from the ample supply. He’d been glad to note that the base was well stocked with coffee, and also with cheeseburger meals that he knew really didn’t taste that bad, despite looking like the mush out of a bad sci-fi movie.

By the time evening rolled around, Dean was weary. He made his routine 21:00 check-in, carefully not telling a grumpy Naomi that he’d possibly met (and then lost) something that might still be a hallucination. After that, Dean had decided to simply watch a movie and put himself to bed. He’d try a surface walk again tomorrow. Some days, he reasoned, were simply not salvageable.

Ares Base had a fairly impressive entertainment system out in the main living areas, and there were also small screens in the dormitories. Hard drives filled with thousands of movies and TV shows had been installed by his robot forerunners, so Dean had almost anything he could think of from the past seventy years of television to watch.

Browsing idly for a few minutes, Dean decided that he needed something cute and silly to distract him after his scare with the creature. He put on an adorable Pixar movie he remembered Sam telling him about, which featured a tiny yellow robot, alone on a planet and wishing for love. Dean sympathized with the little guy a surprising amount.

He programmed the TV screen to turn itself off after one Mars hour, knowing that he’d never make it through a whole movie, tired as he was.

Stripping off his hoodie and sweatpants for a thin sleeping shirt and just his boxers, with no one else to offend, Dean went and sprawled over the bed in his chosen dorm.

With the adrenaline from his terrifying morning having worn out his muscles, it was only a few minutes before Dean drifted off.

He dreamed.

Around him was black; only the periodic twinkling gave it away as space. Somewhere in the distance, Dean saw a beige dot. Well aware that he was dreaming, he shrugged and began to stroll toward it. It seemed to take hours, in this dream; every time thought he was making progress toward the dot, it moved. Finally, he yelled out.

“Come on! I know this is a dream, but I haven’t got all day!”

Annoyed, he trudged on toward the dot. This time, it started getting bigger. Dean could see that it was the alien from a fair distance. He didn’t help Dean shorten the distance, just watched.

Dean snorted as he made his final approach, closing the distance between them in the blackness to just a few feet.

“Great. I escape from you out there, I dream about you in here. Fucking awesome,” he grumbled sarcastically.

The creature did his little head tilt again, apparently in confusion, his blue eyes scanning repeatedly across his face. For a moment, his eyes didn’t hold any recognition.

“Dean,” said Dean cautiously, tapping at his chest as he’d done while awake. “Remember?”

The understanding that spread across the being’s face was clear, and this time, almost eager. He mimicked Dean’s gesture, pulling a hand to his own chest.

“Castiel,” came a voice that was much deeper and more rumbling (and hell, a heck of a lot _sexier_ ) than Dean expected.

Dean grinned, delighted that the creature did seem to be able to speak, at least in his dreams. He parted his lips, about to ask the alien a question—

Dean woke, very suddenly.

He shot up in bed, his heart racing. _What the fuck woke me up?_

Panicking, he scurried for the wall-mounted night light next to his bed, shoving the bedding down to his waist so that he could reach it. Dim, yellowish light filled his corner of the room.

Dean screamed.

There, right next to his bed, leaning over him, was the alien.


	5. Curiosity

Next to the bed, in the dark, stood the man in the trench-coat.

Dean shrieked (rather girlishly, if truth be told) and scrambled frantically back across the bed, tumbling unceremoniously off the other side in a flurry of blankets. He let out an undignified _“Oof!”_ as he hit the floor.

As he clambered back up off the ground, kicking frantically at his bedding, Dean realized that the man wasn’t coming at him. He was, however, holding a rock.

_Is he going to bash my brains in with a rock?_ Dean panicked, flattening himself against the wall next to the bed, wide-eyed.

The alien didn’t seem interested in doing any such thing. His eyebrows pulled together as he peered at Dean, waiting out his shrieking and stumbling. He didn’t move, the rock cupped in both hands. It was a red rock, a little bigger than a baseball. The man could have held it in one hand, but he seemed to be… offering it?

Dean took a few breaths, slowly realizing that there was no immediate threat.

As Dean calmed, the alien took a few careful steps around the end of the bed, moving toward where Dean was pressed back against the wall in fear. He moved cautiously, like he was approaching a wild animal—like _Dean_ was the wild animal.

When he was a few steps in front of Dean, he stopped. Carefully, he extended his cupped hands, with the rock. His mouth pulled into a tiny smile, slightly lopsided, and his blue eyes were soft, almost hopeful.

Shaking, Dean slowly pulled himself off the wall. The alien was giving him a rock. Dean raised a hand forward, just as cautious as the creature was, and reached for it. The closer his fingers got to the rock, the bigger the alien's hint of a smile became. By the time Dean had his hand on the rock, he gave Dean a tiny nod. Looking up at his face, Dean found that the man didn’t look remotely threatening—he looked eager, but cautious. If Dean had to put a human label on it, he’d have said that the alien was smiling at him shyly. 

The rock, Dean realized, was a similar dusty red to everything on Mars, but when he looked closely, it seemed like this one had some tiny crystals encased in it. The scientists would go mad for this. Dean remembered the man returning his sample case the night before. _He saw me collecting samples… and now he’s bringing me a rock._ Dean blinked, looking back up from the strange gift.

“Thank you,” Dean said, slowly, offering the creature a small smile of his own. _You can do this,_ he told himself. _Befriend the curious alien that looks like a low-rent Constantine._

The alien seemed pleased that he’d taken the rock, but uncertain as to what to do now.

On a whim, Dean thought back to the strange dream he’d had as the man was looming over him. Was it just a coincidence, or…?

“Castiel?” Dean asked warily, using the hand not occupied with rock to point towards the man’s chest.

The alien blinked, then a much wider smile began to pull across his features, and he made a small nod once more.

“Your name is Castiel,” Dean couldn’t help but grin too as he clarified. The alien who dressed like a door-to-door vacuum salesman finally had a name. Tapping his own chest again, in a reminder, Dean added, “I’m Dean. Dean Winchester.”

Another minuscule nod.

Feeling much braver now, Dean looked down at the rock. It seemed like Castiel either couldn’t speak or wouldn’t speak, but he did seem to have some understanding of English. “I want to take this to the lab,” Dean pointed down at the crystalline rock, then over to the doorway out of the dormitory. “Is that okay?”

Castiel’s intense blue gaze followed Dean’s indicating finger. For a moment he frowned, processing Dean’s words quite slowly it seemed. When it appeared that he understood, he stepped aside slightly to let Dean pass down the side of the bed.

When Dean did, still a bit leery but also fairly excited that he seemed to be actually _communicating_ with a freaking _alien,_ Castiel began to follow Dean out of the room. He stayed a few steps behind Dean, still watching him like he was very unsure, but kept pace.

Dean found himself laughing under his breath. It was surreal. His new alien acquaintance was coming to the lab with him.

 

~~***~~

 

Castiel seemed very skilled at standing perfectly still. The whole time Dean was in the lab, measuring and weighing the rock and logging it into the system ready for NASA to drool over, he didn’t move a muscle. He stood in the middle of the room just watching Dean work. Staring. It was creepy, but Dean was growing strangely used to it.

When he was done, Dean looked up at the double clock that graced the wall in every room, showing both Mars time and Earth time. It was still very early; Castiel had woken him before dawn. Dean wondered briefly if he could make the alien understand what the phrase “not a morning person” meant. He was doubtful.

“Castiel.” Dean didn’t have to get his attention exactly, as the creature had been staring at him the whole time, but opening a conversation out of nothing felt awkward. “I’m going to get some coffee…” Dean paused to mime a drinking motion. “Coffee. Would you like some? Do you, uh, drink? Like I do?”

Castiel blinked at him. He looked utterly confused.

“Come on.” Dean gestured for him to follow. “I’ll show you.”

That, Castiel seemed to understand. As Dean moved out of the room, the man followed him closely. Dean kept an eye on him as they moved, still very wary. Castiel seemed unfazed by the difference in gravity between outside and inside the base, and Dean had about a million questions about how he was breathing and not sick from radiation. He just wasn’t sure if Castiel would understand his questions, and also—though he told himself it was an odd compunction to have—it just seemed like it would be rude to pepper Castiel with questions about how his alien body worked.

Which led Dean to the thought of what he would tell Benny that night. He only needed to check in with NASA once per day unless he was logging in and out for a surface walk, but eventually, he was going to have to communicate with Houston.  

The thought made him oddly uneasy. Despite his initial fears, Castiel seemed fairly harmless, so far. Curious, nothing more. Dean had some very uncomfortable ideas about what NASA would do with an alien species, should they discover one existed.

Reaching the galley, Castiel stopped in the middle of the room to observe as Dean made his coffee.

On the International Space Station, they had an espresso machine. It made coffee in these little pouches that were perfect for astronauts to drink. The machine, which Dean happened to know was Italian made and had cost a cool fifteen thousand dollars, not even considering the research and development cost, was awesome.

Dean didn’t have that tech up on Mars. They wouldn’t worry about such a thing for just one person; he had the old, instant coffee in little silver pouches. It was terrible as far as Earth coffee went, but it was pretty damn fantastic for space coffee.

After making himself a pouch, Dean brought the coffee up to his lips and took a long, blessed slurp. The world, he hoped, would make a lot more sense after coffee. He let out a long, contented sound after the first sip.

Silent, Castiel stayed in the middle of the room, but Dean could feel the intensity of his curious gaze increase as he sipped.

“Castiel?” He questioned carefully, indicating the coffee pouch. “Would you like some coffee?” He gestured back and forth, trying to indicate what he meant.

Without moving the rest of his body even slightly, Castiel’s head tilted to the side, his eyes following Dean’s hand movements intently. After a moment, he frowned, not quite understanding.

Shrugging, Dean turned and started warming another serving of coffee; the base inventory showed he had plenty, after all. After a few minutes, when it was done, he turned and slowly extended it towards Castiel. “Here,” he ventured. “For you.”

It took Castiel another minute to catch on, still squinting ferociously. When he got it though, an expression of what could only be described as childish excitement came over his face. He took the pouch from Dean almost fearfully, his eyes flicking back and forth between the coffee and Dean.

Dean sipped at his coffee slowly, showing Castiel what he was doing.

After another moment of deliberation, Castiel mimicked him.

The wide-eyed expression that Castiel got after his first sip pulled a laugh from Dean—he couldn’t help it; the alien usually looked so serious, so squinty and curious, that his vivid reaction caught Dean unawares. “Do you like it?” Dean asked, grinning.

Castiel seemed like he wasn’t sure and went in for another sip.

Dean waited, and Castiel kept sipping. He reached the bottom of the pouch before he finally looked back at Dean, returning to his usual stare, and gave another one of his small, shy nods.

Finishing his own coffee, Dean put the pouch into the trash recycler. Castiel seemed to understand, copying him. When they were both done, Dean turned to speak to Castiel as best he could.

“I have to go outside—” he gestured. “I need to change my clothes, and get into a suit, and go set up the sample grid I started yesterday.” Dean had no idea how much of what he was saying Castiel understood, but he seemed to be improving the more Dean spoke, so he decided to carry on the one-sided conversations unless Castiel indicated he should stop.

As usual, Castiel’s gaze moved along with Dean’s gesturing hands, and he seemed to follow somewhat.

Dean walked out into the corridor, heading back down to the dormitories. Castiel followed. In fact, he followed him right into the dormitory. While Dean grabbed some clean boxers and a white t-shirt from his stash, he wondered how he could explain to Castiel that he needed some privacy for a moment. From all his staring and following, the alien didn’t seem to have much concept of personal space.

But then, did he even need to be embarrassed about getting dressed in front of Castiel? He was clearly a whole other species. It’d be kind of like getting changed in front of a dog—if your dog happened to dress like Andy from _The Office_.

_Whatever,_ Dean thought, stripping off his t-shirt and pulling the clean one over his head. As he popped his face out of the neck hole, he saw Castiel staring at him in that weird, clinical way that he watched everything new that Dean did. Dean dropped his hands down to change out of the rest of his clothes and saw Castiel’s gaze follow his hands down below the waist. _Woah,_ Dean paused. _Nope… nope. Not like a dog._

“Castiel,” Dean cleared his throat and motioned with his hands. “Can you go outside, or like… turn around or something?”

Castiel seemed to have another moment of complete incomprehension before Dean’s wild gesturing hit home. _Oh,_ Castiel’s face went. _I see. This is inappropriate._ Swiftly, he spun on his heel and stepped out into the corridor.

Feeling much less self-conscious, Dean made quick work of changing the rest of his clothes and applying some deodorant, taking a brief second to apply a little dry shampoo to his hair while he was at it. All of the water on the base had to be engineered here, and the astronauts that were to stay here would have to get used to dry showers as much as possible. It was fairly standard for most missions though, so Dean was used to it.

Moving out into the corridor, he found Castiel crouched down and studying the door handle of a supply closet incredibly intently.

“Come on, weirdo.” Dean gestured. “Let's get ready to go. Some of us need suits to take a stroll outside.”

 

~~***~~

 

In some ways, as unnerving as it was to have Castiel following him around with his constantly-puzzled gaze, Dean appreciated the company. His fear that the alien was going to do something terrible to him had for the most part evaporated—the man seemed to want to learn about him and be helpful more than anything. 

The spot where Dean had begun marking a grid to excavate samples from the previous sol was about three kilometers from Ares Base. He had previously gone there on Siona the bike, and now he stopped next to her, wondering what to do about Castiel. The alien seemed glued to his side, fascinated with everything that he did.

Technically, the bike-like setup of the vehicle could hold two people, but Dean wasn’t sure Castiel would be pleased with that, given that they could barely hand items to each other without scaring themselves.

He didn’t fancy walking three kilometers through the dusty Martian terrain, however (nor would he be able to), so he shrugged and swung his leg over the bike. Settling into place, Dean gestured to where they were going.

“Castiel, I’m heading back to where I was yesterday, remember? Out there, where you found me?” Dean pointed off into the distance.

Castiel appeared to be listening intently, though Dean already knew better than to expect a response.

“If you want to ride on the bike with me you can, but, uh,” he pointed to the seat behind him, “it’s kinda close quarters up here, buddy.” Seeing that Castiel wasn’t quite following, Dean slid himself back into the second seat, gesturing here and there as best he could to indicate that there was space for two, before returning to his own seat.

Realization seemed to dawn, and Castiel nodded. He gave Siona a very intense squint, almost a distrustful glare. But he looked back up to Dean and seemed to decide that he trusted him— _God knows why,_ Dean thought. He must be as alien to Castiel as Castiel was to him.

After an awkward couple of seconds where Castiel paid rather too much attention to Dean’s thighs and how they gripped the bike, the alien kicked his leg up over her and settled into place.

_I’m riding on a dune bike, in space, with an alien,_ Dean calmly considered. _What is my fucking life?_

Revving up her engine, Dean smiled nervously back at Castiel behind him. He didn’t think Castiel would do anything unexpected, but now that he was on the vehicle behind him, Castiel suddenly felt very close.

“Alright, better hold on,” Dean commented, slowly easing them out from the spot near the base airlock, where he’d haphazardly parked while running from Castiel the day before.

_Was that really only yesterday?_ Dean wondered, kicking up his feet.

Castiel didn’t quite get the memo about holding on. As the bike jerked forward when Dean picked up speed across the sand, Castiel flew forward into Dean, letting out an involuntary “Oof!” sound. It was one of very few sounds that Dean had heard him make at all. He raised his eyebrow and was about to turn his head, to remind Castiel that there was a place on the back of the frame that he could hold on to, when he felt Castiel’s arms slip around his waist and tighten. He leaned into Dean. They were practically the same height, Castiel perhaps an inch or two shorter, and the alien’s face peeked over Dean’s shoulder in their new position. It seemed Castiel had found something to hold on to after all.

Whatever Dean had been about to say fled his mind. He wasn’t uncomfortable, per se. Actually, it was almost worrying how very comfortable with it he was. Pushing the thoughts out of his mind, he pushed the bike faster and zipped across the dunes.

The vehicle was supposed to be purely for practical purposes, of course: increasing the range that Dean and the future scientists could go to gather samples and speeding up their various trips out onto the surface, or aiding with the shuttling of items between Ares 1 and Ares Base. But that didn’t mean, Dean figured, that he couldn’t have fun riding her.

He got the distinct impression Castiel was enjoying it, too. The alien’s arms remained firmly around Dean’s waist, his chest pressed up against the back of Dean’s space suit. When Dean looked to the side to check on Castiel’s face, he saw that his brilliant azure eyes were surrounded by excitedly crinkled skin, his cheeks pulled into a wide grin. Dean thought, if he could speak, he might have been whooping and yelling as they careened over the dunes.

It was almost a disappointment when they reached the flag for the test site.

Dismounting awkwardly, Dean began his slow walk to the grid he’d begun to lay out. It was ruined on the one side, scuff marks through it and sand piled up over the fluorescent thread from his sample case that he’d been crisscrossing around to make divided frame. He must have run over it when he was backing away from Castiel, he realized.

With a sigh, Dean determined that he’d have to start again.

Castiel watched him curiously, from a few feet away. He didn’t have to pay attention to walking as Dean did. The swift breeze moved his trench coat, but sand never seemed to gather on it, and Dean noted with an eerie feeling, even when the alien sat down cross-legged in the dust to watch him, he stayed somehow perfectly clean.

Dean thought on Castiel’s form while he worked. The previous day, Dean remembered thinking that Castiel seemed familiar. Now that he’d had much more opportunity to look at him properly, Dean was fairly certain that Castiel held a very close resemblance to the guy he’d run into on the way out of Trick or Sweet, Gabriel’s bakery back on Merritt Island. In fact, as far as Dean’s memory went, Castiel looked the exact damn same. _But what does that mean?_ he mused. He came up with the slightly uncomfortable idea that perhaps Castiel didn't really look like anything. Either he was a figment of Dean’s imagination (a very solid, warm, bike-sharing one), or he didn’t really look like that at all, and this was some kind of projection from Dean’s own mind.

The idea freaked him out a little, so he pushed it away. Instead, Dean grabbed his sample case and pulled out a trowel and some empty sample bags. He’d take some samples from one of the squares today, to begin obtaining some baseline data for the scientists to work with.

The first bag he filled with surface dust. He opened the second and wielded his trowel, beginning to dig down at the edge of the square to obtain a deeper sample of the Martian soil.

Suddenly, Castiel’s hand shot forward and slapped the trowel out of his fingers.

Looking up, Dean saw that Castiel looked furious. He loomed above Dean, angry, and Dean could have sworn that his eyes glowed as the trench coat flapped around him.

Dean shuffled back slightly in the dust, feeling the same fear he’d held yesterday rising up in him. Castiel was intimidating, despite looking like he spent his days behind a desk picking apart fraudulent tax forms.

“Castiel?” Dean heard his voice quiver. “What’s wrong? What did I do?”

Cautiously, Dean moved back toward the sample grid. However, as soon as his hand reached out toward the trowel, Castiel slapped it away again. The force of the hit threw Dean down onto the sand on his butt, reminiscent of the day before.

Castiel’s eyes widened and he reached forward, seeing what his slap had done, extending a hand to Dean. He seemed to deflate somehow, looking a lot less intimidating all of a sudden. The hit really hadn’t been hard at all, but Dean’s body wasn’t built for this level of gravity. A small tap could send him quite some way if he was caught unawares, as he had been.

Dean could tell though, from Castiel’s worried expression, that the alien didn’t quite understand that. He seemed to be under the impression he’d hurt Dean.

“Hey.” Dean allowed Castiel to pull him back to his feet, then held up his hands in a placating gesture. “It’s okay,” he spoke softly. “You didn’t hurt me. I just don’t understand why you got mad.”

Castiel looked uncomfortable. Actually, he looked downright embarrassed, and it was such an odd expression on his stoic face that Dean felt bad for him.

“Castiel, really,” he tried again, smiling encouragingly. “It’s fine. Just a tap. Don’t use the trowel, I get it. But why?”

Instead of answering, Castiel simply disappeared. There was no poof, no dramatic sound or swooping of the coat. He was just gone, and Dean was left staring at the sand where his alien sort-of friend had been.

_What the hell?_


	6. Doppler Effect

In bed the next morning, Dean didn’t feel like getting up. He rarely did—Benny had been right to comment that he’d never been a morning person—but it was particularly obvious right then. Grumpily, he punched his pillow and forced himself into a seated position.

The day before, after Castiel’s sudden departure, Dean had gathered up his few samples and headed back to Ares Base, alone. He’d anticipated being alone here for the entire mission, of course, so that by itself wasn’t that surprising. But he’d grown used to the strange alien’s presence remarkably quickly, and once he was gone it made the loneliness more pronounced.

When he returned to the base he hadn’t felt much like working in the lab, so he’d spent his time organizing more of the supplies that the robot runs had left in piles in each room. He’d unpacked delicate scientific equipment, food, medical supplies, even rolls of duct tape. NASA thought of everything.

Once he’d grown bored of unpacking, Dean did his regimented daily two hours of exercise. Usually, he would have split them up—an hour when he woke and an hour in the evening. Castiel’s sudden wake-up call that morning had made him miss his first session, so he combined them so as not to get a lecture from Houston. Regardless, the ache in his muscles after two hours had felt strangely good, and he’d decided to place a quick call to Mission Control for his daily report and relax early.

He’d spent some time in the main living area, watching a movie he’d never seen. It was called _The Shape of Water,_ and Dean must have missed it in the cinema because he had no idea that it was about a woman who fell in love with a different species. It made Dean feel odd, so he turned it off toward the end and went to bed.

Now that he was awake again, his odd mood hadn’t much improved. He dressed quickly and decided to get some coffee, shuffling his way through the corridor with a few yawns.

 _Maybe I can get back out to the flag today and finally get the rest of that area sampled if I work hard, now that Castiel has gone—_ Dean’s thought was abruptly cut short as he entered the galley.

In the middle of the room, patiently waiting, stood Castiel.

Dean had no idea how he kept getting in and out of Ares Base without activating the airlock, but really, that was the least of his questions about the strange man.

“Cas,” Dean blinked, stopping in the doorway. “You came back.” Dean wasn’t sure where the nickname had come from; it just slipped out in his surprise.

Castiel squinted at him firmly, as if judging the use of the shortened version of his name. He seemed to accept it, however, offering Dean a small smile that he thought might have been a little sheepish.

Dean moved over toward the coffee machine. Recalling the previous sol, Dean started two pouches of coffee without saying anything.

When he turned back around with one in each hand, Castiel was looking at him almost hopefully.

Dean laughed, more fondly than he expected himself to. “I figured you’d want one,” he commented, offering it to Castiel. “Was this what you came back for? Coffee?” he teased, even though he knew Castiel probably wouldn’t understand.

The look Castiel gave him in return was slightly grumpy—as if he’d picked up on the teasing note in Dean’s voice, after all.

Dean brought the coffee pouch to his lips and moved over to the long table that took up one half of the room. He didn’t feel like cooking, so on the way past one of the cupboards, he snagged a dried meal replacement bar. Ares Base had hundreds of them, so the occasional one wouldn’t hurt, though Dean generally preferred the ‘real’ food.

He lowered himself down into a chair at the dining table and kicked out a seat for Castiel too. The alien did his signature head tilt, regarding the chair for a moment. He looked at Dean, sitting in his own, and slowly copied.

“Alright,” Dean noted. “No chairs where you come from.”

As time went on, Dean was increasingly convinced that the place Castiel came from was somewhere else entirely. He never saw any others of whatever Castiel was; there was zero indication that he actually came from Mars. But how had he got here? Where was his place of origin? Whatever he was, he seemed to have firmly adopted this planet as home. He was part of the Mars package now, and he didn’t really agree with Dean poking at his planet with a sharp trowel.

 _How can I make him understand what I’m here to do?_ Dean mused as he watched Castiel contentedly slurp down his coffee pouch.

Unwrapping his energy bar, Dean threw it into his mouth in one huge piece, pouching out his cheeks like a squirrel as he chewed thoughtfully.

Castiel gave him an odd look that might even have been a little judgey, but turned immediately back to enjoying his coffee.

 _Eating habits judged by the local alien populace,_ Dean thought in amusement. _Matt Damon never had this problem._

When he was done chewing, he stretched out, arching his back as he tensed from his fingers to his toes. His back popped satisfyingly, and when he relaxed back, he noted Castiel watching him intently again. Flushing a little under the creature's attention, Dean sat back up.

“Castiel,” Dean said thoughtfully. “I’d like to show you what I was trying to do yesterday.” He gestured vaguely to outside. “What I do with the things I take. Is that okay?”

Castiel looked blank.

“Let me get dressed and I’ll show you,” Dean decided, finding that holding the conversation by himself and letting Castiel follow along was just easier. “Are you done with your coffee?”

Castiel threw a longing look over to the cupboard where the coffee was kept, as if wishing for more, but he nodded and fell into step behind Dean.

“Personal log, day three,” Dean muttered under his breath. “I have made the alien a caffeine addict.” He smiled to himself in amusement as he entered the dormitory.

Castiel followed him closely, but unlike the previous day, he relaxed enough to perch on the end of one of the empty beds while Dean made his own, gathered up his belongings and searched for clean clothes.

Dean held up the t-shirt, boxers and pants he held for Castiel to see. “I’m going to get changed now, Cas…” he began.

Immediately, Castiel stood up. Clearly, he had paid attention and remembered the previous day, as he turned and headed out of the room.

 _Who’d have thought it’d be so easy to train an alien,_ Dean thought in amusement. The more he mused on it though, as he slid his pants up his thighs, it seemed like Castiel was far too intelligent to be ‘trained’ in any real way. He may not speak, but the way he looked at Dean, the expressions in his eyes, Dean could tell that the creature was very far from stupid. It seemed likely, even, that Castiel was far more intelligent than he was.

The thought sat uncomfortably, so of course, he pushed it away.

Heading back out into the corridor, Dean couldn’t see Castiel. Briefly concerned that he’d disappeared again, Dean called out, “Cas? Buddy?”

He wasn’t sure when or how Castiel had made the transition to ‘buddy’ in his mind, but as he was the only person Dean had on the whole planet, it seemed apt.

Castiel’s head popped out of the observation room at the end of the corridor, responding to Dean’s call. He made his way toward Dean, his footsteps measured and rhythmic across the hard floor. Dean was growing quite used to the way Castiel’s trench coat flapped as he moved around, even if it did look like something a distant relative had gifted him for Christmas that was a couple sizes too big, and he didn’t have the heart to throw away.

“Let’s head on down to the lab,” Dean chatted to Castiel as they walked. “I want to show you what I’m doing with the samples. Maybe if you see we’re just trying to learn, you won’t keep smacking me onto my butt.”

He looked sideways at Castiel as they walked into the laboratory, the biggest room in the base. The alien looked a little shifty; Dean wasn’t sure how much he’d understood, but he thought he caught a trace of embarrassment again.

Giving Castiel a reassuring smile, Dean moved over to a rack on the wall which held gloves, facemasks, and various overalls and aprons. Stepping into an overall, Dean took a pair of disposable gloves and a face mask and moved further down to a hygiene station. Dean had set it up the day before, when he’d wanted to scrub himself as clean as possible after touching Castiel’s rock—nothing personal to the alien, but Dean could do without going home with some kind of bizarre disease he got from touching a rock. Luckily, Mars itself wasn’t radioactive, and neither was the rock, according to Dean’s quick tests. The lack of Earth-like atmosphere left the planet open to bombardment by radiation from the sun, but he shouldn’t have any trouble on that front from the samples themselves. Satisfied that he was clean, Dean slipped on his gloves and mask.

Immobile in the center of the room, Castiel did his watching thing.

“So,” Dean began conversationally, “I come from somewhere pretty far away—Earth.” He gestured to himself, and then up at some of the planetary maps and diagrams that graced the walls. He pointed out Earth on a solar-system map that held co-ordinates and was somewhat surprised when he received an understanding nod from Castiel.

“I guess in the scheme of things though, Mars isn’t that far,” Dean mused. “We’re neighbors, you and me.” He turned to look back at Castiel. “Assuming you’re from here, anyway.”

Castiel looked thoughtful, moving over to the display. He studied the star maps for a moment, then shook his head.

“You’re… not from here?” Dean pointed at Mars on the solar system map.

Castiel shook his head again.

 _Woah,_ thought Dean, impressed to be making such communication progress.

“So where are you from?” He gestured out, encompassing all of the solar system, and the Milky Way diagram next to it, for good measure.

Castiel shook his head again, a little sadly, Dean thought.

“You’re not from anywhere here?” Dean blinked. He was surprised, and yet… he wasn’t. “A whole other galaxy?” he asked carefully.

Castiel nodded.

“And…” Dean bit his lip, a little afraid of the next question. “What about… others? Are the more of you,” Dean pointed at Castiel, then Mars on the map, “here?”

Castiel shook his head again, very slowly. He pointed his finger at his own chest and left it hovering there for a minute, before slowly dropping it to his side. Then he raised it again, gesturing between the two of them, before lowering it again.

“There’s just you,” Dean translated hopefully, “or there was just you, but now there’s me and you?”

Castiel nodded, seeming pleased with his translation.

 _So, before I got here,_ Dean thought, _he was all alone._ The thought hit him somewhere deep and twisted his heart in an odd way, and he found himself suddenly looking away from Castiel, busying himself with the sample case he’d left on the counter yesterday. He still had plenty of things he hadn’t logged.

Flipping open the clasps, Dean pulled out a baggie of red soil. Making sure that he had Castiel’s attention, he moved over to the testing area, offering the alien a warm smile.

“Come on then, Cas. Let me show you what I do.”

 

~~***~~

 

Castiel seemed fascinated with Dean’s process, watching him with silent intensity for several hours as he sifted soil, labelled it carefully, and suspended it in various solutions. He scanned it with various tools to detect its makeup, age and origin—some of the soil on Mars, just as on Earth, didn’t originate there. It had been carried on comets and brought to the ground as they collided with its surface, many millennia before.

Dean took careful notes of everything he did and uploaded them to the Ares Base servers. Dean wouldn’t analyze any of the data. That was the scientists’ job; Dean would have no idea what was significant and what wasn’t, beyond anything obvious. Dean was here to do the grunt work and manage the tech.

Castiel seemed fascinated with every move that Dean made. He followed him around the laboratory, staying out of the way mostly but always watching. No matter where Dean was in the room, a pair of blue eyes rested on him.

Occasionally, while Dean was working, he’d turn slightly as he moved past Castiel, and something out of the corner of his eye looked… different.

He started trying to pay attention to it, but it was very hard to grasp. From a very certain angle, when Dean was moving, it almost looked like Castiel was _bigger._ That his skin was darker, that he had a bulkier shape. Not a humanoid shape at all. But the flashes were so brief, Dean couldn’t get a good look.

Taking into account that it only happened when he was moving, Dean eventually came up with the idea that it was some kind of odd Doppler-like effect. Dean was no scientist, but he was smart enough to think that Castiel’s body must be made up entirely differently than his, no matter what he currently looked like. How else could he walk effortlessly on the surface of Mars? When Dean moved past Castiel at a certain speed and at the perfect angle, it seemed like the form that Castiel projected, or held, or whatever was happening, changed in relation to Dean’s position; like the change in the length of a wave during a Doppler shift.

For just that split second, he realized, he could see what Castiel really was. All he could really tell was that Castiel was dark and hulking, with occasionally visible appendages of some kind. He found that the thought didn’t bother him as much as it perhaps should.

Who cared what Castiel looked like? He was an alien. As long as he didn’t want to eat Dean or something horrifying like that, why should it bother Dean if he wanted to present as an incredibly attractive man who dressed like he sold ad-space for a living?

After watching him for a while, Castiel drifted almost silently over to the hygiene station on the wall. How such a tall, muscled man could move so quietly, Dean had no idea. He watched as Castiel frowned at the sanitizing foam that pumped out of the little tap, slowly rubbing it into his skin as Dean had done. Dean stifled a laugh at the intense concentration on Castiel’s face as he picked up a disposable latex glove.

It took Castiel a few minutes to ease the gloves onto his hands (Dean certainly wasn’t going to try and attempt to explain how to blow in them), but once he had them on, he came cautiously over to Dean’s side.

Dean continued his task, finishing up his notes for his current sample. When he turned, Castiel was next to him, holding out the next sample bag from the container.

They looked at each other a moment, a small understanding passing between them. Whatever concerns Castiel had harbored about what Dean was doing with his trowels and scrapings seemed to have been put to rest. He seemed to appreciate now that Dean was here to learn, nothing more.

With his silent new assistant, the work was much faster.

 

~~***~~

 

Dean seated himself in the observation room, looking out over the deep red ravine that spread off into the distance. Castiel had left some time before, some kind of internal clock telling him that he needed to depart, Dean had guessed. They’d worked for hours, going through all the samples in a comfortable silence. When they had run out, Castiel had frowned down at the briefcase and brought the empty foam insert over to Dean, to show that they were done.

Thanking Castiel, Dean had smiled. Castiel had even managed a small smile in return.

Dean had walked up to the changing room where the suits and sampling cases were stored, returning the newly emptied one to be used again. Castiel had of course followed, slowly learning his way around the base and understanding bit-by-bit what Dean did and where things were kept. Dean headed back to the galley to get himself a drink, and when he’d returned to the lab, Castiel was gone.

Dean had a feeling he’d be back though, this time.

He didn’t understand the human concept of goodbyes, perhaps, but Dean was fairly confident he’d see the alien again the next day.

Alone again, Dean had tidied up the last of the things in the lab before going to get some food and log his exercise hours.

Now he relaxed in the observation room, within arm’s reach of the comms panel, for his daily check-in.

“Mission Control, this is Ares Base. Do you copy?” Dean asked kicking his feet up onto a low table that sat in front of his chair.

“Good evening, Ares Base,” came Benny’s warm drawl. “This is Mission Control. We copy. How’s Mars today?”

“Oh,” Dean grinned, happy to hear a voice after the silence of the day, despite Castiel’s company, “Mars isn’t treating me so badly. I spent the day logging all the samples I told you I managed to gather yesterday, including that really interesting rock sample I found,” Dean lied just slightly. “I think the science guys are going to go nuts for it.”

“That’s good news, Dean,” Benny replied easily. “You got them all logged pretty quick then, working solo.”

Dean paused slightly. He knew he should tell someone at NASA about Castiel. It was important; Castiel’s mere existence was a ground-breaking discovery, something to blow Dean’s little “first walk on Mars” headlines way out of the papers. But, in the back of his mind, something still niggled at him uneasily. He just wasn’t quite comfortable revealing Castiel to anyone.

“Dean? Do you copy?” Benny prompted, after Dean’s silence.

“Uh, yeah.” Dean cleared his throat. “I copy, Mission Control. I worked through them that fast because I’m just that good,” he jested. “Company up here isn’t the best, though.”

“Loud and clear, brother,” Benny agreed. “It’s gotta be a bit rough, that much isolation. Good thing it’s your day to call your family today, huh.”

Dean blinked. With everything going on, he’d forgotten that he could call Sam today. And Jack! His brother and brother-in-law would have their little one home by now—how could he possibly have forgotten that?

“Uh, yeah,” Dean quickly responded to Benny. “I thought I should just check in with Houston first, let you know where I was at for today and what I planned for tomorrow.”

“Seems like today was a winner, so what are you starting on tomorrow?” Benny asked.

Dean was glad that Benny didn’t insist on formal protocol for their chats when he checked in. It was much easier for him to think on the fly when he was relaxed. “Well, I’m going to see what the weather ends up being like,” he replied. “It’s hard to sample when the wind gets up, so I plan to go out every day I can while there aren’t any storms. Then when I get trapped in Ares Base during the dust blowdowns, I can work on logging and interior maintenance, get the more advanced machinery up and running.”

“Sounds smart, buddy.”

“Guess I should go call my brother,” Dean smiled at the thought. “Nothing else to report, Mission Control.”

“Alright, Ares Base. We’ll catch up with you tomorrow, me or Naomi, you know the deal. Stay safe. Over.” Benny’s voice was warm, and Dean already had his fingers crossed that the next check-in _wouldn’t_ be Naomi.

“Bye, Benny. Over.”

Heaving himself up off the chair with one last awed look out of the observation window, Dean made his way back to small room next to the dormitories that housed the software phone on Ares Base. It would give all the astronauts a little privacy while they spoke to their families, without taking up space in the dorms themselves.

Shutting the door to the small room behind him, Dean plopped down into the high-backed chair in front of the bulky machine. It had a series of pre-programmed buttons for calling, and a currently blank screen at face height.

The screen crackled to life as he hit Sam’s number, and Dean waited hopefully.

“Dean!” Sam’s voice came through a second before the picture cleared.

“Hey, Sammy,” Dean grinned widely, his strange feeling from talking to NASA departing almost instantly. “Comin’ at ya, fresh from Mars.” He gestured around at the grey room. “Looks strangely like a broom closet, huh.”

Sam laughed, tucking his long-ish hair back behind his ears as he leaned toward the computer. “It sure does. Is it cool though?”

Dean found he didn’t have to inject any extra enthusiasm into his response. “Dude, Mars is awesome,” he gushed. “It’s kinda weirdly beautiful, and everything here is super fascinating. The base is pretty nice; most of the time it’s not even like I’m on another planet, unless I go outside. I’ve even—” Dean cut himself off sharply.

He’d been about to say, _I’ve even got someone to talk to,_ but he pulled himself swiftly up short. Even if he could trust Sam (which he did, he definitely did), NASA would still have on record everything they said.

“—I’ve even got the gym to myself,” Dean finished lamely.

Sam gave him a slightly odd look, but Dean was spared any question by a shrill shriek off the side of the screen. Sam’s face lit up, and he yelled, “Gabe! Bring Jack-Jack over here, so he can meet his Uncle Dean!”

Dean leaned forward eagerly as his adorable, blue eyed and blonde haired new nephew came into view. “Hey, Jack,” he greeted him softly, and waved.

Gabriel gave Dean a quick wave from behind, holding Jack up so he could see the screen.

“Say hi to Uncle Dean, Jack,” Sam encouraged gently. “See?” He pointed at the screen.

Jack was nearly four years old, but Sam had explained to Dean that he had a speech delay from some of the time he’d spent in and out of care after his mom had passed away. He seemed to have internalized a lot of trauma, but had instantly bonded to Sam the very first time they’d seen each other.

Many people had tried to talk Sam and Gabriel out of taking on the troubled kid, but they were besotted from the start, and Sam firmly believed they could raise Jack to be more than his birth circumstances.

“Bean,” Jack said solemnly, staring right at the screen. “Uncle Bean.”

Dean laughed. “Sure, buddy. That’s close enough for me,” he said, before winking at the screen. “You just wait until your Uncle Bean gets home. I’m going to spoil you silly, and your Dads are going to hate me.”

Gabriel snorted from behind Jack. “Not much chance of that. Sam spent two hundred dollars at the kids’ bookstore this morning,” he teased, but there was a fondness to his tone that he always had when he spoke of Sam that Dean loved to hear.

“Ha!” Sam piped up in turn. “Who was the one that fed him two chocolate pastries for breakfast?”

Dean sat back and watched his little family for a moment as they bickered. There was no doubt, Jack was going to have a wonderful life, the best they could give him.

Dean listened to them coo over Jack and tell tales of what they’d been up to since he arrived, and did his best to pretend he wasn’t jealous at all.


	7. Gravity

Dean had managed to get through his first hour of required exercise, dry shower and dress himself, and be almost done with breakfast before Castiel arrived the next morning. He was making his way down the corridor with a pouch of coffee, heading toward the observation room again. Dean enjoyed the view, and he figured he’d take his coffee there to relax as he was done polishing off his freeze-dried eggs and sausage in the galley.

Dean heard the airlock initiate. The noise made him jump and he was hesitant as he turned to walk back the other way, toward the entrance. But it was, of course, Castiel. Dean had no idea how the alien used the airlock, or what dictated whether he’d use it at all or just appear or disappear at random. The key codes for the airlock were ten digits each, and the likelihood of the alien having _guessed_ the combinations seemed slim. He seemed to somehow activate it without using the keypad, but Dean had yet to catch him in the act.

“Morning, Cas.” Dean smiled as he swept in through the secondary door, once the airlock had adjusted to the Base atmosphere.

Castiel came to a halt, his swinging trench coat settling around his legs, and he nodded at Dean with a wide smile. He looked very eager this morning. He had something tucked under his arm, and once he’d come to a stop inside Ares Base, he took it in both hands and held it out to Dean. The serious eyes and tiny smile were back, trained hopefully on Dean.

Dean realized that Castiel was holding one of Ares Base’s sampling cases—the exact one, Dean realized, that they had emptied together the day before. He could tell by a few small scratches on the metal exterior, from where Dean had dropped it onto the rocky ground and abandoned it, when he and Castiel had first met.  

_He must have taken it when he left yesterday,_ Dean thought, puzzled. _Or come back for it during the night, maybe?_

Taking the case from the alien, Dean realized that it was very heavy. “What’s this, Cas?” he asked, curious.

Castiel gestured for him to open the clasps and take a look inside.

When Dean got it balanced on one hand so that he could open it with the other, he realized that it was packed full of samples. A complete set, even with the coded labels attached to show where on the sample grid they came from.

“Woah, Cas…” Dean blinked up at him, meeting Castiel’s eyes. “Did you collect all these? For me?”

Castiel gave an emphatic nod, but then bought his hands together in front of his chest, knotting his fingers for a moment before they fell back to his sides. It seemed to be a nervous gesture, and Dean realized that he wasn’t certain he’d yet seen the alien make any gesture at all that wasn’t deliberate.

“Hey, it’s fine—you did good, Cas, this is great!” Dean reassured, smiling and nodding in a slightly exaggerated way as he closed the case. “You did, like, a whole day’s work for me.” Dean grinned.

Dean was pleased that the message seemed to have gotten through to Castiel that he was just here to learn, and that he wasn’t trying to damage anything or anyone with his sharp trowels and loud instruments. And if the alien’s way of trying to befriend him was to do his job for him, well, he wasn’t going to complain.

Slurping the last of his coffee from his pouch, Dean arranged the case so that he was carrying it by the handle.

“Do you want to come back to the lab again, Cas?” he asked, gesturing to it down the corridor with the hand that held his empty coffee. “Do you want to work with me,” he pointed at his chest, then Castiel, and then back to the lab, “like we did yesterday?”

Castiel nodded seriously as they moved back toward the galley for Dean to place his pouch in the trash recycler, but Dean didn’t miss the way the alien’s eyes had rested very briefly, but longingly, on the empty coffee pouch.

Without really thinking about it, Dean reached across and put a hand on Castiel’s shoulder, smiling. “How about we get you some coffee first?” he offered.

Castiel blinked, turning his head to look down at Dean’s hand on his shoulder for a long second. He looked surprised, and Dean thought for a moment that he should apologize. But when Castiel looked back at him, he smiled the tiny, shy smile Dean had seen the day before. His face never changed much, but the increasing frequency of the little quirks of his lip had to be a good thing, Dean decided.

“Alright then,” Dean nodded, moving over to make another coffee.

When he went to pass it to Castiel, the alien clasped Dean’s hand between both of his, still holding the pouch. They held there for a moment, a few seconds longer than would have been entirely polite or normal for anyone else, before he took the pouch, his shy smile turning thankful.

_That’s his little way of saying thank you,_ Dean thought, warmly. _We’re learning to communicate just fine._

Castiel walked by Dean’s side as they progressed down to the laboratory, sipping contentedly on his coffee. He made no sounds, but his eyes lit with enjoyment.

Dean smirked as they moved into the white, sterile lab. “I don’t even know if you’re coming here for the company or just the caffeine, at this point,” he teased, grinning as he began to pull on his overall.

Castiel looked blank, tilting his head quizzically.

“Right,” Dean muttered to himself. “Don’t tease the alien. He’s never going to get it.”

When Dean was dressed to work, Castiel stepped up to the station and sterilized his hands before slipping on a pair of gloves and a facemask, as he had the previous day.

Castiel sorted and sifted, Dean logged and stored. They worked well, and the hours flew by.

 

~~***~~

 

The next morning, Dean waited at the long galley table for Castiel, with coffee already made. Castiel seemed delighted when he realized that Dean had made him a drink in anticipation of his arrival. He lowered himself into the chair next to Dean, quite the expert at this chair thing now. He even leaned back into it a little, rather than sitting stiffly.

Dean watched Castiel openly, as the alien seemed to have no qualms about staring at him constantly. Personal space or comfort seemed to be a human concept that did not extend as far as Mars, or whatever other galaxy it was that Castiel originally came from.

Every time Dean saw Castiel, he seemed to be relaxing a little more. Dean too, was finding himself more and more comfortable in the alien’s presence. In fact, he mostly forgot he was some kind of separate species—it was more like having a friend who didn't speak the same language, in Dean’s eyes. They managed.

When Castiel was done with his coffee, Dean tossed their empty pouches into the recycler and turned back toward the table, to find that Castiel had risen. He looked at Dean expectantly, a question in his eyes as he pointed toward the laboratory.

“Actually, Cas,” Dean laughed, “we did so well yesterday with all those samples you bought here for me, I’m really ahead of schedule. My superiors must think I worked all night,” he said gratefully. “So, I don’t really need to spend any more time in the lab today. I could collect some more samples, or start checking the outside of the Base for maintenance tasks…”

Although Dean was mostly talking to himself, not really expecting Castiel to understand, the alien was watching him intently, his head slightly tilted as he took in every word.

Raising one hand, Castiel cautiously reached out to place his hand on Dean’s forearm, drawing his attention back from his musing. He pointed to the lab, and then shook his head, as if checking his understanding.

Dean mimicked him, smiling, trying to confirm. “That’s right. No lab.”

Castiel looked thoughtful.

Dean wasn’t bothered by Castiel’s touch on his forearm, but he wasn’t quite sure what to do with it. He was about to lower his arm, dropping away from Castiel, when the alien’s hand slid down to the underside, moving along to catch his hand. Dean looked down in surprise.

_I’m holding hands with an alien,_ he thought. _Why is he—_

Castiel pulled gently, pointing toward the exit lock. When Dean didn’t immediately move, Castiel stepped outside the galley door into the corridor, tugging at Dean’s hand and continuing to point.

_Oh,_ Dean understood. _I get it. He wants to lead, today._

“You want to show me something, Cas?” he questioned, allowing himself to be led along the corridor. Castiel’s hand felt firm, slightly calloused and warm. Just like a human hand. Dean looked down, studying Castiel’s strong, tan fingers as they squeezed around his own, leading him firmly, though not roughly.

Dean was so focused on Castiel’s hand in his that he almost walked into his back when he stopped. Catching himself, Dean looked up to see Castiel pointing quizzically at the changing room.

“Oh,” Dean found himself flushing slightly. “Right, yup. Space suit. I need one of those.”

Castiel waited patiently while Dean pulled his freshly charged suit from Ares 1 on over his comfortable base clothes. As usual, he stood eerily still, just staring at Dean until he was done.

Dean stood and moved to the airlock comms, wondering what he’d have to say to Benny. He placed a finger in front of his lips, indicating to Castiel that he should be quiet. The alien fixed him with a confused look, and Dean laughed at himself. _What am I doing? Dude never speaks anyway, he isn’t gonna start now._

“Mission Control, this is Ares Base. Do you copy?”

“Hey brother, this is Mission Control. I copy.  Got a problem up there?” Benny asked, his warm drawl filtering clearly through into the airlock.

“Not at all, B. Just going out for a surface walk. Saw a spot the other day I think we might want to test, so I’m going to check it out now I have a fully charged suit,” Dean lied smoothly.

“Sure thing, Dean,” Benny responded, relaxed. “No problem. Time out?”

“9:01 Mars time, over.”

“9:19 Earth time. Keep safe brother, don’t let the aliens probe you too deep.” Benny jested lightly as the airlock initiated. “Report in on return. Over.”

Castiel gave Dean a funny look, tilting his head to the side.

“Uh… never mind that, Cas,” Dean muttered awkwardly once the comms had disengaged. “Just an Earth joke. You ready?” He indicated toward the opening

They stepped out together and settled onto the dusty red planet. The door to Ares Base closed behind them with a hiss and a very final-sounding series of clunks.

Castiel stepped forward. He reached down again to Dean’s hand, attempting to tug him in the direction of the dune bike.

Dean froze. Just for a moment, he looked down at his hand in Castiel’s, and panicked. Was he really about to let a freaking _alien_ just lead him off God knows where, on a strange planet, with no one knowing where he was going?

_Am I crazy?_ he thought, gazing down at their hands. Then, he looked up.

Castiel was looking back at him, patient and trusting. He looked completely open, huge blue eyes gazing softly across at Dean while he waited. Dean got lost in Castiel’s eyes for a few seconds longer than was probably polite, but it made his decision for him. Flushing slightly at having stared for so long, Dean stepped forward, allowing Castiel to lead him along the dunes.

Once Dean had swung into his seat on Siona, Castiel mounted up behind him just as he had the first time they’d ridden together. Without preamble, Castiel slid his arms around Dean and leaned into his back, hooking his chin over Dean’s shoulder. Raising one arm, he pointed in the opposite direction to the test site Dean had already been too, leading them around to the other side of the ravine that Dean could see from Ares Base’s observation room.

His uncovered face next to Dean’s visor, Castiel smiled. _Trust me,_ his eyes said.

So, Dean did.

They sped along on Siona for twenty minutes or so, leaving Ares Base far behind.

The scenery of Mars turned out to be far more spectacular than Dean had imagined. The wind was fairly low, and he could see for kilometers out in front of them. He brought the bike to a halt, informed by a tap on his shoulder from Castiel that they had arrived.

Dismounting, Dean took a look around, wide-eyed.

Castiel had brought him to a wide open plain, surrounded by jutting rock formations that the eternal wind had twisted into fascinating shapes, like Martian totem poles. Dean knew that some scientists, though not all, theorized that there was once a huge, primordial ocean on Mars, many millennia ago. Dean always felt he didn’t know enough of the science to have an opinion, but this area certainly mimicked a sea bed fairly well. The sand was slightly deeper here, a soft landing that went on almost as far as he could see.

It was eerily beautiful, and he guessed his expression conveyed it well enough, as Castiel stood off to the side, stock-still as always, but smiling almost proudly.

Dean wandered this way and that, studying the alien rock formations in awe.

“Cas.” He turned to look over at the alien, grinning through his visor. “This is amazing—it’s beautiful here.”

Castiel nodded, almost thoughtfully, then crooked a finger to indicate that Dean should come over to where he stood. When Dean arrived at his side, Castiel gave him a look that could only be described as mischievous.

“What?” Dean asked, squinting curiously at the alien.

_Watch me,_ the alien hand gestures went.

Turning so that he faced nothing but kilometers of wide, red sand, Castiel bent his knees. He took a couple of steps, building up a little momentum, before he turned to look back over his shoulder at Dean. With a wink, he jumped.

Dean was well aware of the effects of gravity; he’d spent hundreds of hours in low-gravity environments, and many, many hours studying the concepts back at the NASA academy. Nonetheless, he hadn’t spent much time considering how Mars would affect jumping. It wasn’t the moon, after all. Even so, there was a lot less gravity than back home.

Castiel’s simple jump took him easily four feet into the air. He stayed airborne for several seconds, before landing in the soft sand with his trench coat flapping around him.

He turned, a wide, gummy grin plastered across his face and gestured that it was now Dean’s turn.

Dean took a few more steps than Castiel had to build up momentum and launched himself into the air like an Olympic long-jumper, aiming for further, rather than higher. He flew past Castiel, hollering with surprise as he sped through the air, feeling weightless.

Castiel moved back to his side in a series of sweeping bounces, before Dean bent his knees and pushed, using all his force to zoom directly upwards. Dean screeched in delight, hovering far above the ground for a few seconds before his downward trajectory towards Castiel began again. The alien grinned widely up at him. As Dean came back toward him, Castiel reached out, and pushed hard against Dean’s feet, shooting him back up again.

Whooping with glee, Dean did a full backflip before landing safely in the sand. Laughing, he bounded back up to Castiel.

“Cas, this is awesome. It’s like a Martian trampoline park,” he said, reaching for Castiel’s shoulder familiarly.

Castiel made the same little head tilt he always did when he didn’t know what Dean was saying, but smiled anyway. He reached across into Dean’s space, settling his hands onto Dean’s hips in the space suit. His look was questioning, seeking permission for something.

Dean nodded and braced himself.

Castiel pushed upward, launching Dean off the floor again, and twisted Dean as he let go. Dean pirouetted furiously up into the air. Laughing again, Dean brought his arms in like a ballerina, seeing how many spins he could get in before he hit the floor once more.

Dean and Castiel simply played around for almost an hour, the silence of the planet broken by Dean’s laughter and yelling. Castiel may have been silent, but the twinkle in his blue eyes was almost the same thing.

 

~~***~~

 

The running machine in Ares Base’s gym beeped contentedly as Dean transmitted his exercise stats to NASA, confirming that he’d hit his two-hour requirement for the day. His thighs ached badly, but he suspected that might have a lot more to do with all the jumping and flipping he’d done with Castiel earlier than the exercise itself.

They’d played like kids for a while, spinning and flipping in increasingly more gymnastic patterns, trying to one-up each other in jump height or distance. Dean had a great time, and he was pretty sure Castiel did too. The alien never seemed to tire, unlike Dean, who had eventually had to call a halt to their fun and beg to return to Ares Base for food, water and a little rest. Castiel seemed happy enough to accompany him back.

In fact, it seemed to Dean that the alien was genuinely enjoying his company, which made Dean feel a little better about the fact that he was too. Even if Castiel was a strange, unknown species, they had enough in common to appreciate each other in the loneliness of space.

Strolling to his dormitory to take a dry shower before sleep, Dean considered Castiel.

Several times now, Dean had experienced the phenomenon of catching Castiel out of the corner of his eye, and sensing something… else. Just as in the lab when he’d first noticed it, Dean had found that out on the sand bed, he hadn’t ever been able to get a fix on quite what he was looking it. It made no sense. (But then, Dean considered, as an alien, did Castiel have to make sense?) Castiel definitely looked bigger. Darker. Possibly even like he had many more appendages than Dean was used to. Why then, did he look like the handsome dude from Gabriel’s cake shop? Increasingly, Dean suspected that his current appearance may just be to make Dean himself more comfortable.

Would he be freaked out, if Castiel looked so terribly different to him? Dean pondered as he cleaned himself up and idly flicked through the TV menus to find a movie. He supposed it wouldn’t matter, not now that he was reassured that Castiel wasn’t a danger to him. More than that, that Castiel was friendly, and thoughtful, and kinda sassy and amusing in his silent way.

Castiel had left a couple of hours before, after returning to Ares Base with Dean and somehow charming another coffee out of him before his departure. He’d thanked Castiel for taking him out to the sand bed, and while he wasn’t sure if he understood every word, the meaning seemed to get across. They’d given each other’s shoulders a squeeze, and Castiel had begun to move back toward the entrance, looking back before he turned the corner to fix Dean with a thoughtful look. What he was considering, Dean had no idea.

Dean reclined, fluffing his pillow. _I wonder if Cas would want to stay and watch a movie, one day? He could learn a lot about Earth that way,_ Dean considered. _I wonder if they have movies where he comes from… They don’t seem to have chairs, or coffee, but he has no trouble with airlocks or the equipment in the lab. Strange._

Dean didn’t make it through more than a few minutes of the movie, worn out by the exercise and his fun alien excursion. As soon as he fell asleep, though, he began to dream.

He immediately recognized the endless black star-field in the dream. This was where Castiel had told him his name.

Dean looked around, wondering if perhaps Castiel had brought him here again to say something, since he didn’t seem able to speak in his humanoid form during Dean’s waking hours. A quick look around, though, showed no beige spot in the distance for him to approach.

He wandered, calling out, “Cas! Castiel? Are you here?”

An endless amount of dream-time seemed to pass before Dean sensed something behind him. He turned, and there Castiel was, standing a few feet away.

“Hey, Cas. Wanted to keep me waiting this time, huh?” Dean grinned.

A corner of Castiel’s lip quirked in a smile, and he stepped up toward Dean. He reached out, grasping for his shoulder lightly. Castiel didn’t speak, simply regarding his hand on Dean’s shoulder before he looked up.

They stared at each other for a moment, before Castiel dropped his arm and shifted back out of Dean’s space. His hands came up in front of his chest, making the same nervous finger-knotting motion that Dean had seen him make when he brought the samples to the base, unsure if Dean would be pleased.

“What’s up, Cas?” Dean asked, trying to sound as soothing as he could. “What are you trying to tell me?”

After smiling nervously once more, Castiel disappeared.

Dean sighed. It was slightly irritating that the alien could do that, he had to admit.

He wandered again, through the twinkling blackness of his dreamscape, though this time it didn’t feel as long until he felt something watching him.

When he turned, his jaw fell open involuntarily.

The creature that watched him was huge. Its body was so black it was hard to pick out a shape from the darkness around him, but with a lot of squinting, Dean thought he could see two colossal wings. They protruded from the back of a vaguely humanoid shape, he thought, except… something moved. _Tentacles_ , Dean realized with a jolt. _He’s got fucking tentacles._ Massive, fantastically blue eyes were the only feature that really stood out against the black. They were bigger than dinner plates, and peered down at him curiously, the azure irises almost seeming to swim and move, like fantastic blue constellations.

Dean studied what he could see for a minute, taking the creature in.

_It’s Castiel,_ he decided. _I’m sure of it. This is his way of trusting me, showing me in a safe way. This is what Castiel looks like—tentacles and all._

Almost as soon as he thought it, Dean woke.

He looked around. Other than the voices from the tail-end of the movie he picked murmuring in the background, he was completely alone.


	8. Telescope

Time seemed to pass oddly on Mars. Although one sol was barely different from an earth day, the low sunlight that wandered its way through the thin atmosphere made each one seem long. The dim light didn’t provide the ‘awake’ feeling that stepping outside in the morning on Earth did; the permanent twilight feeling clinging from rising all the way back to sleeping.

Although Dean had to report in to NASA daily, he was left to form his own schedule for the rest of the time, and the lack of imposed structure made one day flow seamlessly into the next.

Over the passing weeks, he and Castiel developed a simple but solid routine of their own.

Dean would wake and make enough coffee for two. Some time after he’d dressed himself and dry showered, Castiel would appear—sometimes through the airlock and sometimes just materializing in the galley.

They’d sit together at the table and drink quietly until Dean woke up a little more. Then they’d usually head out to one of the sixteen identified sample sites NASA had suggested. They’d ride the dune bike together, easy and content, enjoying the feel of flying over the dirt as Dean pushed the bike just a bit, spinning in the sand and leaping a little more than was necessary over every ridge.

When they were done, they’d head back to Ares Base for Dean’s lunch. Sometimes Castiel would disappear for a little while Dean ate; sometimes he’d stay. He’d never shown any interest in the food, only coffee.

The afternoons they would spend either working in the lab together, side-by-side, or Castiel would accompany Dean on maintenance tasks around the base. There were machines to set up for the incoming scientists, checks to perform on the less-used rooms of the base, more dust shields to raise outside, almost endless improvements to be made to the technology that provided Dean’s environment. It was work Dean enjoyed, even more so with Castiel’s help.

With his aid for all his tasks, Dean got through an amount of work each day that was astounding to NASA. He had successfully hidden Castiel’s existence from them so far, so they just thought that Dean was incredibly efficient. It wasn’t a bad reputation to have, he decided.

Throughout the sols, Dean would chat idly; it seemed like the more speech he exposed Castiel to, the more astute he became at ascertaining Dean’s meanings, though Dean wasn’t sure if he would ever try to speak. He was fairly sure that Castiel had the capability—once when they’d been adding new solar panels to the roof of Ares Base, one had slipped and hit Castiel in the chest. It wasn’t a severe hit, but it drew a small “oof!” sound from the alien as he was knocked back. He’d communicated to Dean that he felt no pain, and Dean had actually been glad for the mistake—just that tiny noise was quite exciting, after weeks of silence. But still, no matter how comfortable they became, Castiel didn’t say a word.

He smiled, though. Increasingly, more and more each day. It turned into a game for Dean, discovering what would pull the wide, gummy smiles out of the alien. Sometimes it was something completely unexpected, like when he was able to show him the concept of blowing bubbles, within the controlled gravity of Ares Base. Sometimes it was something very simple; coffee with Dean in the mornings. Other times, it seemed random—Dean would look up and catch Castiel staring at him as he often did, and when Dean’s eyes met his, the smile would creep across his face. It was effortless to return it.

They became comfortable in each other’s spheres. Castiel had never seemed to have any concept of personal space, often standing just too close and never turning down the opportunity to stare at Dean with his vivid, azure eyes. Dean grew used to it and found himself gravitating toward the alien just as easily. Out here in the loneliness of space, it was easy to miss the casual touch of another person—a handshake, a brushing of hands as someone gave change, a clap on the shoulder. These little touches became second nature between the two of them, and Dean was certainly helped by them.

The mental health of astronauts was always of huge concern to NASA. Naomi had Dean check in with Dr. Mia Vallens every two weeks. A soft-spoken woman, Mia was a specialist psychologist who was responsible for monitoring astronauts in various locations. She watched for signs of developing disorders that could easily be caused by the loneliness or claustrophobia of their situation. Dean passed every assessment with flying colors; Mia joked that he must have been born to be a loner on Mars. Dean liked her. He was certain, though, that he had Castiel to thank for his great mental state—he was having fun on Mars. In fact, he loved being there, spending his days with Castiel.

Only at the end of the day, when Castiel left for the evening, did Dean ever feel lonely. Increasingly, Dean wished he could somehow ask him to stay—but he didn’t push his luck.

 

~~***~~

 

Six weeks into his Mars residency, Dean finally got the telescope set up. The scientists that would arrive just days after he left would use it to take measurements and map the Martian sky, similar but just different enough from the way Earth saw it. It hadn’t been a priority to set up, but Dean had, by this point, done almost everything else required of him.

Snapping shut the heavy metal door that shielded the wiring within, Dean grinned proudly at the giant, electronic telescope.

“There we go, all done,” he said as he pulled off his gloves.

Castiel, stood to his right, tilted his head in Dean’s direction. He looked inquisitive. _Great, but what is it?_ he seemed to say.

“Wanna see?” Dean asked with a grin, gesturing toward the controls.

Eagerly, Castiel stepped up to them with him. The panel of controls was extensive. The telescope was powerful and could take extremely high-resolution pictures of very distant celestial bodies.

Thoughtfully, Dean toyed with the controls, then looked at Castiel.

“Would you like to see Earth?” he asked, suddenly realizing he could show Castiel his home. “Do you wanna see where I come from, Cas?”

Dean made a series of gestures between himself and the spot where the telescope disappeared into the ceiling.

Castiel frown with concentration, following Dean’s hands with his eyes but not quite getting it.

Reaching out and grasping the alien’s hand, Dean led Castiel quickly up the corridor to the lab. Castiel’s hand fit easily into his, familiarly, and he went trustingly along with him. When they got there, Dean drew him over to the star maps on the wall.

“Earth, remember?” he pointed to the planet on the map, then back to himself. “Where I come from.”

Understanding spread quickly across Castiel’s eyes and he pointed back to the telescope room, nodding. He got it. He seemed pretty keen once he’d picked up on Dean’s meaning, and pulled Dean quickly back to the telescope behind him (as their hands were still linked).

When they were back in front of the control panel, Dean tapped his way through the navigation to find the pre-set locations. Part way down the alphabetical list of planets, stars and distant galaxies, was Earth. Pressing the coordinates into the telescope, Dean gave it a few minutes to adjust and focus.

Once the telescope’s lenses had moved into position, the screen in front of them flickered and came to life.

Looking at the magnificent blue and green sphere that filled the five-foot screen, Dean felt and odd pang of homesickness. It was strange to realize that other than the moments he’d spoken with Sam, Gabriel and little Jack, he really hadn’t missed Earth at all.

Castiel looked almost awestruck. He reached up, cautiously spreading his fingers on the screen, standing so close to it that the picture reflected blue-green and cloudy white onto his lightly tanned face.

Wide-eyed, with a small smile, Castiel gestured between Dean and the photograph of the planet.

“Yup,” Dean said, almost fondly. “That’s my home.”

Castiel’s head tilted very slowly. After a pause, he brought his hand up to the screen again, pointing between the photograph and himself. The motion was small.

A twinge of something Dean couldn’t identify hit his chest as he interpreted Castiel’s question: _Can I come too?_

Dean was suddenly very aware that when he had to leave, in just a couple of short weeks, Castiel would be all alone again. The thought left a sour taste in his mouth, and his rib-cage ached.

_It’s not fair,_ Dean thought. _I wish he could come._

He shrugged helplessly, his smile regretful. “I don’t know, Cas,” he responded quietly. “If you wanted to come, I’d—I’d like that. But I don’t know how. I have no idea how I’d get you off this planet, or if you’d even be okay there… Ares 1 can only carry one person, that’s all she was made for.” 

Dean gulped suddenly, unsure why the realization hit him so hard.

Castiel listened as Dean spoke. He’d used a lot of words, more than he’d usually say to the alien in one go, trying to break down his speech to be as helpful as possible. But this time, Castiel seemed to understand without any further prompting.

He nodded slowly, his eyes dropping. He gave Dean a small smile before he disappeared.

It was hardly the first time Castiel had vanished, but it was the first time in a long while that Dean worried he wouldn’t come back.

_Maybe he didn’t understand,_ Dean worried. _Maybe he thought I just didn’t want him to come?_

The thought that he might have hurt Castiel’s feelings sat very heavily at the forefront of his mind as he lowered himself into the spinning seat before the comms console.

“Mission Control, this is Ares Base. Do you copy?” Dean asked, wondering how long Benny would be able to chat tonight.

“This is Mission Control, Ares Base. I copy,” Naomi’s crisp voice came through the speaker, making Dean’s mood even worse.

“Reporting in for my dailies, Mission Control,” Dean offered with a sigh. “Where’s Benny at?”

“One of his children has the flu, Ares Base,” Naomi responded, not unkindly. “So, I’ll take your stats and report today. Over.”

“Loud and clear, Mission Control,” Dean responded, hoping that he didn’t sound as disappointed as he felt.

“Begin report, Ares Base. Earth time 19:12.”

“Mars time 18:47. Base stats are—” Dean leaned forward to squint at a few screens. “—1159, 86, 3.7, 912. Outdoor wind speed finally dropped from yesterday; back down to 7 meters per second. I managed to get out and dust the solar panels off this morning,” he confirmed.

The conversation passed back and forth, formal and to the point. When they were done, Dean signed off almost glumly; he’d really been hoping to chat with Benny.

“Goodnight, Mission Control. Ares Base out.”

Dean heard a soft noise behind him. Jumping and spinning, Dean saw that Castiel had materialized out in the corridor once more.

He raised a hand in a little wave; a greeting that Dean had taught him the second week they’d known each other.

Standing quickly enough that the chair continued it’s spin without him, Dean smiled widely with relief and moved over to Castiel. He came to a halt right in front of him, suddenly unsure.

“I-I’m sorry, Cas,” Dean offered softly. “I don’t want to leave, you know. I wish you could tell me if I hurt your feelings somehow. I didn’t mean to.”

Castiel watched his face as he talked, giving him a tiny, sad smile. He seemed to have taken whatever time he needed to compose himself, but nonetheless, he seemed subdued.

Dean battled the overwhelming urge to hug him and say sorry again.

_He’s not going to know what it means,_ Dean considered. _He might not like it._

Even so, Dean found himself very cautiously raising his arms. He made sure that Castiel was watching him, mirroring his melancholy smile.

“See, sometimes when people—well, humans at least—are sad, a hug can just… feel good,” Dean tried to explain, quietly. “This is a hug,” he added, gesturing Castiel forward.  

Castiel was trusting, despite his apparent low mood. He very slowly mimicked Dean’s movements, until Dean had his arms around him, and he encircled Dean in turn.

Slowly, Dean ran his hands up the back of the trench coat. It was a soothing motion, he hoped. Castiel was stiff for a moment, uncertain, but as Dean’s strong hands spread at his back and moved, he relaxed by inches until he was leaning slightly into Dean.

“That’s it,” Dean murmured. “I’m sorry, Cas. I’m going to miss you, if that means anything.”

Dean let out a sigh, and Castiel’s arms tightened slightly in return. A few seconds later, Castiel slowly sunk his head down, resting his cheek against Dean’s shoulder. It seemed to be a natural movement, something Dean hadn’t specifically showed him, but that came to him automatically.

Dean smiled; it seemed like some things were instinctual for any species.

Castiel didn’t know any etiquette regarding how long hugs were supposed to last, but Dean found he didn’t care. They stood for several minutes, just holding tight.

 

~~***~~

 

Not too much later, Castiel began to stand from his seat in the kitchen. Dean had decided to cheer Castiel up with coffee, something that for the most part seemed to have worked.

As Castiel gestured toward the airlock, his nightly signal that he’d leave Dean to rest and have his private time, Dean’s hand darted out to Castiel’s wrist.

“Wait—” Dean said, surprising himself. “You don’t have to go.”

Now that he had truly realized that his time with Castiel was going to be limited and would be ending soon, Dean didn’t want to waste any more of it. He could have time alone when he got back to Earth, in his lonely apartment, where hanging out with aliens wasn’t an option.

Dean gestured down the corridor to the room where the main entertainment system was; a kind of relaxation-room for the inhabitants of the base. “We could watch a movie, if you wanted. You could stay.”

The head tilt happened, of course, but Castiel followed Dean to the couch in front of the large screen in the wall. Dean grabbed the remote and dropped down into the pillows. After a few seconds of observation, Castiel mimicked him. He sat too close, but Dean just laughed and shook his head: _of course_ he sat too close. It was Castiel.

“These are movies,” Dean indicated the screen, scrolling through near endless images on the screen. “NASA really does try to make sure we don’t go too nuts up here,” he grinned.

Castiel showed no understanding but nodded politely.

Dean carried on flicking through the movies. “Oh, this is classic!” he exclaimed after a minute. “My friend Charlie back home, she’d be mad at me if I didn’t start with this,” Dean intoned solemnly, referring to the bubbly, red-headed dork that he’d shared an apartment with for all of college.

Castiel’s eyes moved back and forth between Dean’s face and the screen.

“The Princess Bride,” Dean announced with a little fanfare, throwing the remote down next to him and kicking his socked feet up on to the coffee table.

As the image on the TV began moving, Castiel’s attention was drawn to it. But after a moment, he looked back at Dean, studying his form up and down intently. Used to the inspection, Dean just smiled as Castiel very carefully copied him, kicking off his sensible shoes and resting his toes—in pristine white socks—up onto the table next to Dean’s.

He leaned back as Dean did, and for the first half of the movie, they just watched.

Feeling a tiny chill, Dean reached over to grab a blanket that he’d left here a few days before. As he flapped it over himself like a sail, his eyes slid sideways to Castiel.

The alien was rapt, his gaze solidly locked on the screen. He even leaned forward slightly, coming up off the back of the couch just the smallest fraction as the movie caught his attention.  

The blanket was nice, but something about seeing Castiel so entranced warmed Dean more.

He turned his attention back to Westley’s adventures on the screen and lost himself in it for a few minutes. Until, very gently, he felt a tug on the edge of the blanket.

Castiel was looking over at him, his big blue eyes resting on the side of Dean’s face, until Dean turned to look at him. Castiel pulled suggestively at the blanket, a small, hopeful smile gracing him as he tucked himself beneath it next to Dean. Just doing as Dean did, like always. Follow the leader.

Within seconds, Castiel was wrapped back up in The Princess Bride.

Dean could feel Castiel against his side, warm and solid, and he found his gaze drifting from the TV to just watch Castiel as he in turn watched the movie.

_He looks happy,_ Dean thought, letting himself stare. _He’s even more handsome when he’s relaxed._

The thought wasn’t a shock, Castiel’s body did, after all, seem to be based on the form of the hot dude he’d crashed into back at Trick or Sweet in Merritt Island. But Dean realized, with slight despair, that the warm stirrings in his chest and stomach as he studied Castiel’s profile didn’t really have much to do with how he looked.

_Don’t be mushy, Dean_ , he told himself firmly. _Cas is an alien. He didn’t even know what a hug was. He’s not even the same species. Rein it in._

Turning his attention back to the TV, Dean kept it firmly in that direction until the credits rolled.

“What did you think?” Dean asked with a smile, as if Castiel could answer.

He met Dean with one of the gummy grins; the first Dean had seen all day. He was glad for it, and immediately grabbed the remote. Pressing it carefully into Castiel’s hands, he moved Castiel’s finger back and forth, showing him what the buttons did.

“I’ve got to head to sleep, Cas. But you can stay,” he indicated the couch. “You can watch more movies, if you want. If you want to stay.”

Castiel watched his lips move. He seemed to study the words very intently, and when Dean was done he moved his gaze slowly between the TV, and the bedroom, and Dean, and the couch.

He nodded. The gummy smile came back again as he relaxed against the couch.

Dean grinned, because Castiel’s message was pretty clear: _If you want me to stay, I’ll stay._

Leaving the blanket to Castiel, Dean moved toward the door. With some amusement, he watched from the doorway as Castiel selected “When Harry Met Sally” from the menu.

_We’re going to have to work on his taste in movies,_ Dean thought, finding it a little funny.

“Night, Cas,” he called as he began to move toward the dormitory.

There was, of course, no reply.


	9. Retrograde

Dean had grown very used to the silence of Ares Base. Outside, Mars could be surprisingly noisy, with constant winds and shifting sand dunes. Even the flat planes of sand creaked and hissed in the wind. When vicious dust devils blew in during the stronger storms, the ones that kept Dean confined to Ares Base, Mars positively howled. But the Base itself was soundproof, and the ferocious gusts didn’t break the tranquility Dean was now accustomed to living and sleeping in.

So, when he woke and heard the soft murmur of voices and laughter, Dean jolted upright. Something was wrong, was his initial thought—but no. It was just the entertainment system in the break room, he realized. Either Castiel had really actually stayed, or he hadn’t known how to power down the entertainment system (or even that he should, perhaps) when he left.

Forcing his sleep-scrambled legs out of bed, Dean shuffled across to the doorway of the dormitory and out into the corridor. He wore his staple base uniform of soft grey sweatpants and a matching t-shirt—both NASA-issued and crumpled from sleep. He was sure he had crazy bedhead and morning breath, but why should he care about that? He had no one to impress, up here.

Even so, he found himself trying to straighten his clothing and run his hand through his hair a few times before he approached the door to the entertainment room.

All the interior doors in Ares Base were white plastic frames with glass windows top and bottom, mostly see-through but with enough of a frame to hide the mechanisms that made them slide open and closed with the press of a button. Dean raised his hand to pop the switch to let himself in, when he spotted Castiel still on the couch.

Dean’s hand hovered above the button, but he didn’t press it.

It seemed the Castiel didn’t sleep—or at least he hadn’t last night. He still sat where Dean had left him, on the right-hand side of the long couch directly in front of the wide screen. He’d shifted positions in Dean’s absence, at least; the blanket was tucked up to his hips, his shoes still off, but he sat cross-legged on the sofa now, leaning forward slightly. He was totally engrossed in the TV, a soft smile just teasing at his lips. He didn’t watch passively, though, his eyes occasionally darting around the screen as new objects or characters came into view. It was like he was drinking in every image, eager and not wanting to miss even a minute detail.

_He’s learning,_ Dean realized. _He’s taking in every last little thing._  

He’d definitely been a quick study on everything Dean had to do in the lab or the engineering tasks around Ares Base. He’d learned to pilot Siona, he’d learned to communicate with Dean, in his own way. Dean had never had to show him anything more than once.

Dean was in no doubt that the alien, despite his lack of speech, was hyper-intelligent. He probably knew things Dean couldn’t even fathom. Yet, he’d been completely baffled (and then utterly delighted) by the way the Base microwave pinged when the food was done.

Dean stood at the door, just watching him for a few minutes. The body the alien had adopted, or projected, or possessed, or whatever the hell it was he was doing, was utterly gorgeous. Dean had no qualms about admitting that much, alien or no. His messy, dark hair, his mesmerizing blue eyes, his perfect white teeth and soft-looking tanned skin all added up to six feet of pure, muscled sex. If the alien had somehow plucked perfection from Dean’s memories, he’d done a great job.

But what Dean was hung up on, more than how beautiful Castiel was, were the glimpses he got from the corner of his eye now and again. If the creature he’d seen in his dream was Castiel—and he couldn't really begin to work out how to bring that up—then why did he appear like this? Did he not trust Dean?

_Is it because I’m human? Is he like this to make me more comfortable, or for himself? Does he feel safer?_ he thought. Dean’s chest beat strangely as he remembered that he hadn’t let anyone at NASA know about Castiel. And he believed that was the right choice. Perhaps using this guise was actually safest for him. Who knew what Dean’s colleagues, or the government, or any other agency, would do to Castiel if they knew he existed?

A brief cold chill passed through Dean, before being instantly replaced by a warm, protective feeling.

Dean realized, watching the completely fascinated alien gaze up at the TV, that he would do anything to keep Castiel safe from that. The idea that he cared about him was easy and comfortable. They were friends, at the very least, he felt; if Dean’s feelings were perhaps growing into something else… that was his business. Messed up business maybe, but his alone.

Looking up at the screen, Dean smirked and shook his head when he realized Castiel was watching _Dirty Dancing._

Peeling himself away from gazing at the alien, Dean shuffled off up the hallway to make them both some coffee.

_Dude has terrible taste in movies,_ he considered, grinning. _Luckily Swayze always gets a pass._

Once he had the coffee in hand, Dean actually hit the button to slide open the entertainment room door. Castiel looked up immediately, greeting him with a wide, warm smile.

“Morning, Cas.” Dean found himself returning it in equal measure. “Brought you some coffee,” he explained needlessly, moving over to sit next to him on the couch. He could have sat in any of the other seats, or on the other side of the couch, but the spot right next to Castiel was where he’d sat last night, so why not?

Castiel nodded gratefully, reaching to give Dean’s hand a small squeeze in thanks for the coffee.

Dean just watched Castiel for a moment, as his lips sucked down the first sip of his drink. After a few long seconds, he cleared his throat, ripping his eyes away.

‘“So… movies. You liked them?” he asked, gesturing to the TV.

Castiel’s nod was emphatic.

“I should show you how to use the internet,” Dean said with a small laugh. “You’d love that.”

Castiel quirked his head to the side, of course, and before they knew it, Dean was pulling up an extra chair in the comms room and introducing Castiel to the web.

Accessing the internet from Mars was actually one of NASA’s most recent technological innovations, and something of a miracle. They’d had internet access on the International Space Station since way back in 2010, and even the moon had very little latency, though the bandwidth sucked. But with very recent advances and upgrades to NASA’s Deep Space Network, innovations in laser communications and various network boosts now available between Mars and Earth, it had become quite possible. Dean was grateful—he hadn’t used it himself a ton, but he knew he was going to be happy for it now that he could show Castiel.

With a few clicks, he found himself on YouTube. What was more important during an internet education than cat videos, after all? Castiel’s face lit up as Dean clicked through a few links.

“I guess you won’t be able to search for what you want by typing since that would involve knowing Earth languages,” Dean mused, “but you can click through links and suggestions like this—” he paused, guiding Castiel’s fingers to the trackpad on the desk.

After a second, Castiel nodded, with a grin. He began to click through link after link, wide-eyed and utterly engrossed.

Dean squeezed his shoulder fondly. “Knock yourself out, Cas. I’m going to grab a dry shower and change into my lab gear,” he said, standing.

Castiel couldn't even tear his eyes from the screen long enough to look at Dean while he nodded, caught up in a video of a bat eating grapes.

_Adorable_ , Dean couldn't help but think, as he moved out of the room.  

 

~~***~~

 

Dean worked in the lab for a couple of hours, tracking the samples that had been logged to make sure they had the range they required before he was scheduled to leave in a couple of weeks. He hadn’t heard a peep from Castiel, so he pulled off his gloves and tossed them into the recycler, deciding to go check on him.

The noise, as he approached the comms area, was layered and confusing.

_What the hell is Cas watching in there?_

When Dean made it through the doorway, he blinked in surprise. Castiel had learned how to open new browser windows, and now had several spread out across the multiple monitors. All of the videos were playing at once, and he was sitting calmly, taking them all in simultaneously. One was a video showing how engines worked. One appeared to be an episode of Scooby Doo. One was a video covering the decline of honeybees, and another showed what looked like some kind of Korean drama that had two boys shyly holding hands on the screen.

“Woah, Cas,” Dean said, coming up behind him. “You can watch all this at once? And learn from all of them?”

Castiel’s wide, blue eyes moved across from the screen to Dean, and he gave a little smile as he nodded. Reaching for the trackpad, he paused them all, and pointed to the laboratory.

“Nah, I’m done in the lab for now,” Dean answered, reaching for a clipboard that he always kept on the desk showing specific tasks he needed to complete before his departure. “What I should really do today is go and take efficiency readings from the wind turbines on the other side of the ravine.” Dean gestured hopefully in the correct direction. “The ones that we fixed up to give extra power to the base,” he reminded Castiel.

Following Dean’s gesture and perhaps recognizing some words, Castiel nodded again and stood.

He pointed in the direction of the airlock, one finger flicking between himself and Dean.

“Yup,” Dean grinned. “Of course I want you to come.”

It only took Dean a few minutes to get into his space suit, and once he’d double checked everything and quickly checked out with Benny, they were on their way.

Today, Dean decided to let Castiel control the dune bike, indicating to him that he should get on first. He looked pleased, as if he found it to be an honor that Dean would let him drive.

Settling his muscular thighs easily each side of the bike frame, Castiel looked back over his shoulder and smiled at Dean to indicate that he was ready. Dean hopped up behind him, getting comfortably settled. He placed his hands respectfully on Castiel’s shoulders to steady himself.

Castiel moved them out from the parking spot where the bike charged overnight, turning to head toward the nearby ravine. He then paused for a moment, turning his head to look back at Dean. For a moment their eyes met through Dean’s visor. Castiel reached up, pulling Dean’s hands off his shoulders and settling them on his waist.

Dean felt himself flushing slightly as he slid them further, wrapping his forearms around Castiel so that they were pressed together.

_Cas does this when I drive,_ Dean reminded himself _. He’s an alien; it doesn’t mean anything to him to be this close._

Flying over the sand toward the wind turbines, Dean couldn’t lie to himself how much he enjoyed the feeling of Castiel’s body between his legs, though. He pushed the thoughts away doggedly.

_You’re an idiot, Dean. Stop it. Alien. Alien._

Drawing the bike to an almost expert halt beneath the first of the huge wind turbines, Dean caught a small, proud smile curling Castiel’s lip.

“Great job driving,” Dean couldn’t help but give Castiel a little squeeze and a wink before he hopped off the bike.

Castiel looked at him strangely, but didn’t react other than to follow him silently over to the thick metal base of the turbine.

Pulling out his monkey wrench from the tool bag that lived on the back of the bike, Dean began to loosen the bolts on the panel that shielded the inner workings of the turbine from all the dust that routinely blew around the planet. Some of the red sand had heaped up around the bottom of the turbine since Dean had last been here, but most of the time it blew away again just as quickly as it accumulated. 

He worked quickly, much more efficient than he would have been without Castiel to pass him tools and hold wires, always watching with quiet intensity. Dean rarely if ever had to prompt him, the alien seemed to be able to anticipate his needs just by observing. It made for a very comfortable working relationship and enabled Dean to check off another maintenance task in a lot less time than he expected.

“Thanks, Cas,” he said, turning as they walked back to the dune bike to give the alien what he hoped was a very sincere, warm smile. “You’ve really been a huge help to me. I’m really glad that—”

Suddenly Dean stumbled on one of the many loose red rocks that littered the surface of the world, carried around by the strong winds. He flung out an arm to steady himself in his clumsy space suit, but the low gravity caused his motion to be a little wilder than intended. His balance off, Dean fell onto his knees. He would have ended up smashing his face into the ground, if it hadn’t been for Castiel’s hand shooting out to grasp at his.

Castiel held on, continuing to support Dean as he awkwardly clambered back to his feet.

“Damn rocks. Thanks, Cas,” Dean began. He meant to offer his friend a grateful smile, but Castiel wasn’t looking at his face at all.

Instead he stared steadily down at their entwined hands.

They’d held hands several times before, dragging each other around the base in excitement or to show the other something. Castiel didn’t seem interested in personal space and they’d exchanged perfectly friendly touches many, many times over the weeks—even hugged, before, when Dean had shown Castiel how.

But now it looked different. Their hands weren’t just held. As Castiel had grabbed out toward Dean’s hand and when Dean had returned the motion, their fingers had entwined. The thick fingers of Dean’s space suit had worked in between Castiel’s tanned ones, and they had tangled together and held in a gesture that somehow, now Dean looked at it, felt far more intimate than it had been intended to be.

For some reason neither of them had pulled away. Unsure, Dean gave Castiel’s hand a small squeeze before he dropped it.

“Thanks,” he said again.

Castiel’s eyes finally came up, blinking, and he nodded slowly. He didn’t step away back toward the bike, so for a moment they just stood, a fraction too close, looking at each other.

There was _something_ , in Castiel’s eyes, Dean was certain.

Nervous and suddenly awkward, Dean dropped his gaze and hurried back to the bike. Castiel stood still, thoughtful for a moment, before he followed him.

 

~~***~~

 

“Mission Control, this is Ares Base. Do you copy?”

“Ares Base, this is Mission Control. We copy. How’s it going, spaceman?” Benny drawled warmly, his strong voice filling the comms room.

To Dean’s left, Castiel sat in one of the chairs with eight videos from various websites spread out in front of him, listening to them all on headphones. Dean couldn’t help a fond smile as the alien leaned forward in excitement to click _Game of Thrones_ along to the next episode.

“Not too bad, Benny,” Dean responded, tearing his attention away from Castiel so that he could complete his check-in. “I did the final efficiency checks on the three wind turbines that are twelve kilometers from the Curiosity landing site.”

A low whistle rattled through the speaker. “Really, brother? You’re steaming through that list NASA compiled, aren’t you? They’re gonna have to think of more for you to do.”

Dean laughed, grinning even though Benny couldn’t see him. “They’re gonna have to think of giving me a raise,” he suggested. “Though I doubt it.”

Benny’s chuckle seemed to be an agreement he was hoping for too much. “Alright Dean. Well, all the stats you submitted look great according to the Engineering guys, so I really don’t have much to ask. I’m supposed to let you know that the weather team have told me not to authorize any base departure tomorrow, though.”

“Oh?” Dean asked. “Not going to be a nice day for a walk?”

“Winds could be up to 96 km/h,” Benny said seriously. “So, you better listen, pal.”

“Don’t have to tell me twice,” Dean agreed. “I’ll find something to do in the lab, or just watch some TV.”

“You’ve earned a relaxing day or two, I should think. Check in with us during the evening though, as usual.”

“Will do, Benny. Over.”

“Mission Control signing off, Ares Base. Goodnight.”

As soon as he’d hit the key to disconnect from the Johnson Space Center, Dean stood up from his chair and gave a long, back-cracking stretch. He stepped left and leaned over Castiel’s shoulder, taking in all the videos Castiel was watching.

The internet was a weird, time-sucking hole of a place and Castiel seemed to be devouring and learning everything from cooking shows to _Days of Our Lives_ , documentaries about the Incas to grandmothers giving solemn testimonies on World Wars. One of the screens even seemed to be showing what Dean was fairly sure was the beginning of a terrible porno about a pizza delivery. He shook his head with a quiet laugh.

“You really do want to learn _everything,_ don’tcha Cas?” Dean asked, unable to help how fond his voice sounded.

Castiel turned, slipping his headset off to look up at him. His nod was very solemn, but he chased it with a little grin.

“Are you going to stay here tonight, Cas?” Dean gestured down to the off-duty portion of the base. “Or will you head back out to wherever you go?” His hand then indicated the changing room and airlock.

Castiel tilted his head thoughtfully, regarding Dean. His hand came up to point down to where Dean’s had—the entertainment room with the TV, down the hall, and the general area of the galley and dormitory. When his hand moved, it didn’t drop back down, instead point across to Dean. He tapped one finger lightly at Dean’s chest. _I want to stay,_ Dean deciphered. _I want to stay with you._

Dean felt the back of his neck heat slightly, and he raised a hand to rub at it.

_Not like that, dumbass,_ Dean thought to himself.

“Well,” Dean said, “I have to get some dinner.” He stepped away from the comms seats and headed toward the doorway. When he reached it, he stopped, resting the heel of his hand on the doorframe as he looked back at Castiel. “Would you like to have dinner with me, Cas?”

_Not. Like. That._ Dean thought again, with an internal sigh. _Seriously, what the hell is wrong with me today?_

Castiel’s eyes brightened and he gestured to the galley, before lightly touching his mouth with two fingers.

Dean nodded.

Castiel smiled, wide and gummy, and fell into step alongside Dean as he made his way to dinner.

It wasn’t much; space food wasn’t that fancy. But they did have carefully packaged and preserved lasagna, and in celebration of the first real meal that Castiel would spend with him, Dean even planned to bring out some of his carefully rationed apple pie.

They sat on adjoining sides of the table, with the corner between them. Dean chatted idly about the food, telling Cas about the great lasagna he could make back on earth, and how this was amazing for space food, but nothing on his.

Castiel tried a small nibble of the noodles and sauce, a deeply curious expression etched across his face. He swallowed it, but Dean noted that he didn’t reach for any more. He wondered if the alien had to eat at all.

“What about you, Cas?” Dean indicated him with one hand as he asked. “Do you eat anything?” he reached up and very cautiously tapped one finger against Castiel’s bottom lip. He felt Castiel inhale sharply, and Dean dropped his hand immediately.

“Sorry.” Dean held his hands up carefully. “I just wondered how you survive if you don’t eat.”

Castiel nodded slowly, as if understanding, but didn’t seem able to offer any answer. He sat and watched Dean quietly, following each bite up to his lips with his unwavering blue gaze.

They had both fallen into comfortable silence by the time Dean brought out the pie, so it only seemed natural to Dean to keep his voice low as he said, “I must really like you Cas, because anyone who knows me will tell you that I do _not_ share pie.”

He gave the alien a little wink as he broke the buttery crust of the pie with his fork. The pie was kept frozen so as to preserve it in space, so it didn’t come anywhere close to the fantastic slices Dean’s brother-in-law sold at Trick or Sweet (or that Dean could bake himself). But it was tasty nonetheless, and a huge delight after the fairly plain and nutritious offerings that NASA usually had their astronauts stick to.

_The first thing I’m going to do when I get back to Earth,_ Dean decided, _is head straight to see Sam and little Jack… and get some of Gabe’s pie._

Easing a forkful into his mouth, Dean let out a shameless groan.

He opened his eyes to see Castiel staring at him, his mouth hanging slightly open.

Dean could have been embarrassed, in theory, but Dean Winchester didn’t do shame when it came to pie. Instead, he eased another mouthful of the slice onto his fork and offered it to Castiel.

There was a moment before Castiel leaned forward. A moment where their eyes met, and Dean struggled to think much beyond _Cas._

His lips parted and settled around the fork, and Dean slowly withdrew it from Castiel’s mouth, watching him the whole time. Castiel chewed slowly. He swallowed; a much harsher gulp than the pie probably called for, but regardless, he smiled wide when he was done, nodding.

“You like it?” Dean asked, leaning slightly forward in his seat, already thinking about giving Castiel another bite.

Castiel nodded solemnly, and his wide smile reduced down to something smaller; a soft, almost shy look that Dean squinted in puzzlement at.

Castiel’s hand reached out to Dean’s face, and Dean froze, confused, until he felt Castiel’s thumb gently dislodge a pie crumb from the corner of his mouth.

_Oh._

“Thanks, Cas—”

Dean was cut off by Castiel’s lips on his. He didn’t move forward particularly fast, cautious and uncertain about it, but Dean’s brain didn’t register what was happening until his mouth was no longer alone.

It felt _right._ Dean’s veins reacted by running hot fire straight to his heart, and his heart reacted by forgetting to beat for a moment. Unfortunately, his mouth’s only reaction was a startled “Umpfh!”

Castiel drew back, and his eyes were wide. His mouth hung open slightly, his chest rising and falling as he breathed heavily. He looked terrified.

Dean put the fork down quickly, planning to reach for Castiel’s shoulder, reassure him it was okay—and damn, kiss him back—but before any of that happened, Castiel disappeared.

“Shit,” Dean hissed into the silence. He sighed. _Way to go, Dean._

  



	10. The Big Bang

**Notes for the Chapter:**

> We're finally going to earn our explicit rating in this chapter.
> 
> Do I make any apologies for calling the NSFW chapter "The Big Bang"? Nope, not a single one. 
> 
> Enjoy!

Dean stayed up pretty late, hoping that Castiel would reappear. By the time he dragged himself reluctantly into the dormitory, his eyes were drooping. He hadn't been able to settle since dinner; he’d skipped his evening exercise hour, too distracted to think about it. Hopefully Naomi wouldn’t complain about it, just this once.

He lowered himself down to the edge of his mattress with a slight groan, suddenly feeling his age and then some. He rubbed his hands over his face.

 _You really fucked up, asshole,_ Dean berated himself. _How much time and persuasion and courage must it have taken him to make that step, and all I could manage was “Umpfh!”, like a moron._

Sighing out loud, Dean looked around the room.

“Hey Cas…” he said, feeling like an idiot talking to himself. “I don’t know where you go when you disappear. Like, if you’re still here and I just can’t see you, or…” he trailed off, scratching his fingers back across the crown of his head. “I’m really sorry. Please come back. You just took me by surprise. I actually, well—” Dean laughed awkwardly. “I’d really like to kiss you. Please.”

Admitting it out loud, Dean could suddenly feel it deep in his chest, like hot air filling his lungs.

_I do want to kiss him. I don’t care if he’s an alien… I really like him. Shit. Great going, Dean._

Too annoyed with himself to read or put on a movie, Dean simply huffed and rolled onto his side on the bed. He’d taken a quick shower, rubbing the dry shampoo angrily into his hair, but he still felt unpleasant.

 _Might as well just go to sleep,_ he thought sadly, punching his pillow into shape and knocking off the light.

It wasn’t clear how long Dean had been asleep before he slipped back into the dark star-plane that seemed to have been his constant dream world of late. He’d only interacted with Castiel here twice, but every time he had dreamed of it since the first, he’d felt something (or someone) watching him. Even if he couldn’t see them. It wasn’t creepy, or malicious, in any way; he felt protected. Watched over.

Tonight, something felt different.

He felt an emptiness that echoed between the twinkling stars, so much _nothing_ that it was something.

“Cas?” Dean called out, standing still and peering around, trying to see any kind of speck on the horizon. “Castiel! Where are you?”

After a few minutes with no response, Dean began walking.

He walked and walked.

He figured he’d walk until he woke; if he didn’t find Castiel, at least he’d tried.

The feeling changed very suddenly, the _thereness_ of something behind him a sudden jolt to his senses. Dean whirled around.

“Cas?”

The alien towered above him, black against black. He looked down at Dean with his hauntingly blue eyes, the only real color on his dark body. He was mostly humanoid, other than huge wings and the tentacles that were on full display from the waist down. The being’s face had essentially human features, though his eyes were disproportionately large. Dean was so, so certain that this creature was Castiel. So much so that he stepped up towards it.

“Cas? Is that you?” Dean asked, softly, not stopping his forward movement. He was much taller than Dean and the size difference between them was even more exaggerated by the huge wings that projected out above his back, towering over them. “Cas, if it’s you—I just want to say sorry. I didn’t mean to hurt your feelings.”

He smiled at the alien creature and eased forward just a little more, one hand carefully extended in front of him.

The being didn’t move at all. It seemed frozen, just watching Dean with colossal blue eyes that studied his every inch with an intensity that Dean was certain could only possibly be Castiel’s.

Even though it held itself still and unyielding, Dean could sense nervousness from the alien. He was only moving by inches, not wanting to spook him, but now, if Dean could just reach out—

One of the tentacles rose. It was thick and dark, with a purplish tinge. The end of it was smooth as it drew to a point, but Dean could see lighter colored suckers like an octopus would have, running along its length further back.

Swallowing down his nerves, Dean reached out to meet it. The flesh was warm to the touch as it rested against his palm; just the very tip at first, but then curling gently and sliding over his skin. It was softer than he expected, and while undeniably kinda damp, it felt silken to his touch, like wet velvet.

He felt like he should say something, tell Probably-Castiel ( _Hopefully-Castiel!)_ that it was okay, that he didn’t mind what he was, that he liked him anyway. But he didn’t really know where to start.

So instead, Dean looked up at the black, solemn face that barely stood out from the starscape around him. The creature was wide-eyed, as if this was just as wild for him as for Dean, his sight locked onto Dean and his reactions. Carefully, Dean used his other hand to crook his finger, gesturing for the alien to duck down slightly, to Dean’s level. Its face was dark and difficult to read, but its features looked perfectly humanoid, if bigger in scale.

When the face, with its giant blue eyes, came down to hover nervously in front of his own, Dean gave him a reassuring smile.

“It’s okay, Cas,” he soothed quietly. “I know it’s you. It has to be.”

Running his eyes one last time over the alien features in front of him, wrapping his fingers loosely around the tentacle that sat in his palm, Dean leaned forward and pressed his lips to the creature’s own.

It didn’t make a sound of surprise like Dean had earlier done in the galley, but it blinked several times, its head tilting to study Dean as he pulled back from his quick, experimental kiss.

Dean was about to beg the creature to give him _some_ indication of what he was thinking, when he felt tentacles sliding across his back, his neck, his sides. He was being fully… embraced? Dean looked at the tentacles, which were moving slowly and gently.

 _Is this… a hug?_ Dean thought, doing his very best to stay calm. _It’s gotta be Cas. It’s gotta be._

With that thought, everything disappeared. Dean drifted back to dreamless sleep.

 

~~***~~

 

Dean had never been the type to wake quickly. Usually, unless something jolted him awake, he’d snuggle back into his pillow and ignore his alarms multiple times until he eventually, with much complaining, struggled to the kitchen for coffee. When he woke the morning after his dream of Castiel, it was different.

His eyes opened, and he reached to rub the sleep from them immediately. He was alone, but his heart was pounding in his chest. There was no point in saying that “it was just a dream”, Dean knew. The other dreams he’d had of Castiel, when he’d told Dean his name, when he’d first shown Dean his true form, those had all been real. The knowledge he’d gained within them had held up during the daytime.

So that meant his dream last night was just as real.

Castiel may have kissed him unexpectedly when they had dinner, that may have been innocent on Dean’s part—but in that dream, Dean had been the one to make the move. He’d chased Castiel down, and hoping that the huge, winged and tentacled beast was really him, he’d chosen to kiss him. At no point had Castiel cajoled, tricked or bamboozled him. He’d wanted to give Dean another chance and make sure, it seemed, that Dean knew what he was really getting into. 

So now Dean knew.

 _I chose to kiss the alien,_ Dean thought. _Tentacles and all. That was all on me._

He was less uncomfortable with it than he thought he would be. When Castiel had clumsily pressed his lips to Dean’s while in his human form, Dean hadn’t had a single doubt. Fire had roared through his veins around that dinner table; he had no doubts that he was attracted to Castiel. And even then, he’d known. He’d already assumed, as close as damn near sure, that the creature from his dreams was Castiel.

Rolling onto his side to turn off his beeping alarm, Dean smirked slightly to himself. It was almost funny, really. Back on earth, Dean had a top-secret stash of a very particular type of Japanese pornography that’d he’d never told anyone about, though he suspected that his brother knew. It wasn’t exactly mainstream, Dean knew, but it was just a fantasy—a tentacled fantasy, that had kept him company on many a lonely night. The fact that Castiel actually had tentacles, even if Dean only saw them in dreams… well, if he was honest, that just made him even more attractive.

A movement at the doorway caught his eye.

Castiel stepped quietly into the bedroom, clutching a pouch of coffee. He looked nervous and regarded Dean wholly uncertainly as he stepped up toward the bed.

“Morning, Cas.” Dean managed to give him half a smile. He hoped it came across as warm, but he was nervous, too. Did kissing someone in a dream really count? How was he supposed to act now?

Dean had almost made up his mind to apologize for chasing Castiel down and kissing him when Castiel lowered himself down to Dean’s bed. The firm foam mattress gave a little under his weight as he settled himself down in the space created by the curve of Dean’s body as he lay on his side. He turned so that he was facing Dean and pulled one knee up onto the bed, so he could fully look at him. From stomach level, where he sat, Castiel could easily reach forward to offer Dean the coffee he clutched reverently in both hands. He smiled, shy.

“You bought me coffee,” Dean registered, returning Castiel’s smile with one of his own. “Coffee in bed, that’s awesome. Thank you, Cas.”

Castiel seemed to understand his thanks. He ducked his head slightly as if to say, _You’re welcome, it was nothing._  

Dean slowly wrapped both of his hands around the coffee. His fingers brushed Castiel’s, and for a minute their eyes caught, staring at each other with matching wide-eyed, almost amazed expressions.

 _That was his step,_ Dean thought, taking a few quick gulps of coffee to wake himself and at least replace his morning-breath with coffee-breath. _He took a step. Coming back here, greeting me with coffee. So now I should._

Placing the coffee pouch onto the small nightstand, Dean pushed himself up on the pillows and reached, cautiously, to take Castiel’s hand as he spoke.

“That’s you, right?” Dean began. “The huge creature,” he gestured way up high with his free hand, before pointing to Castiel, “the one I see in my dreams? I thought it was you, but now I’m sure.”

Castiel nodded. It would have been a bashful gesture, except for the fact that his eyes locked firmly on Dean’s the whole time. As if waiting for something else, some confirmation.

Dean grinned. He didn’t want Castiel to have any doubt. Shuffling slightly forward on the bed, he leaned in toward the alien and raised his hand, cupping his cheek so reverentially, so carefully, that it took Castiel a second to register. He looked puzzled, until Dean carefully stroked his thumb across Castiel’s skin.

Castiel’s eyes widened.

“I like you, Cas,” Dean said, strangely not embarrassed or shy at all; perhaps something to do with knowing that Castiel probably wouldn’t pick up on the words themselves, so much as the overall meaning.

The warmth that lit Castiel’s eyes was unmistakable. He knew what Dean meant. The breathtaking smile that spread over his face gave way to a nod, then several nods, small and eager.

 _I like you too, Dean,_ they said.

It was Castiel that leaned in, taking the opening that Dean had offered to press his lips softly to Dean’s. He pulled back after only a second, Dean’s hand still on his cheek, but he didn’t panic or run, this time.

So, Dean pulled him back in, deepening the kiss with a content sigh. Castiel's lips were pillowy and slightly dry, but warm like the rest of him as they fell into sync with his own. Dean let himself tumble into it, his tongue teasing out to slip along Castiel's bottom lip. When the alien admitted him and twined his own silken tongue with Dean's, he tasted like coffee.

Dean was still sitting in bed, Castiel perched on the side of it. It seemed only natural and polite for Dean to shift to the side, making room beside him on the mattress. Dean expected some caution from Castiel, perhaps some lack of understanding, but it seemed that now Castiel was reassured they were both on the same page, his shyness had evaporated.

He lowered himself down on the bed and lay on his side, reaching one hand to bring their lips back together. The other slid around Dean’s waist, eliminating the space between them with a surety that Dean found quite arousing.

On his side, so close to Castiel, Dean could fully appreciate the million blues that made up his eyes, and the gentle crinkles at his temples as he smiled and kissed. He could feel Castiel’s firm chest against him, and one of his thick, muscled thighs worked between Dean’s own as the slide of their mouths intensified.

This close, Castiel had a slightly spicy, ozoney scent, like too-fresh cold air and feather dust, that seemed to almost seep out of his pores. It was intoxicating, and Dean found himself trying to commit the addictive, unique smell to memory.

Dean was aware that he was making noises; gasps and soft grunts as he felt Castiel tighten his arms around him, drawing them eternally closer. He’d always been a vocal partner, and he was getting lost in Castiel. The intensity of the sounds he made, so early on, didn’t give him any embarrassment here.

The alien seemed to enjoy the groans. Between kisses, he reached up to rub one finger along Dean’s bottom lip, before sliding it softly down to his neck, just the tip trailing along Dean’s skin. Dean thought, for a moment, that perhaps Castiel was tracing Dean’s voice, his vocal cords, considering how Dean worked. But it didn’t matter, really, because Dean found the gentle, trailing touch incredibly erotic. His voice left no doubt on the matter as he moaned quietly under the attention.

Almost like he was experimenting, Castiel followed the trail of his finger with his tongue. Dean writhed, making a louder sound then, gasping the alien’s name out almost involuntarily.

The gaze that Castiel met him with was hooded, but his eyes were soft and adoring in way that Dean had never seen them. In a way that he wasn’t sure he'd ever seen on anyone.

“Cas,” Dean rumbled breathlessly. “What—” he paused, to lick his lips and put a couple of inches between them, so he could voice an important thought before he got carried away, “—what do you want, Cas?”

Castiel tilted his head slightly, causing it to rise off the pillow a couple of inches.   

“Do you—” Dean tried again, sliding his hand slowly down Castiel’s side, inch by inch, pointedly.

Castiel’s expression gained understanding. Reaching for Dean’s face, he slowly dived back in; the kiss was the sweetest Dean could remember, causing him to gasp again from that alone. The adoring look in Castiel’s eyes held as he pinned Dean in his gaze, punctuating the softness with a very pointed roll of his hips against Dean’s.

The motion, and the solid, eager length that it pressed up against Dean, left him in absolutely no doubt that not only did Castiel want to take this further, but he knew exactly what he was doing. 

Dean groaned again, his only response before his hands slid back up Castiel to his chest. He pressed back into the tender kiss, changing the tone of it to something more heated, but no less full of feeling. Easing his fingers up under the edge of Castiel’s trenchcoat, Dean pushed it suggestively from his shoulders.

The coat spread out in a puddle as it slid to the floor.

Castiel lay back on the pillow and grasped one of Dean’s hands in his. He led Dean’s fingers to his shirt buttons, demonstrating silently what he wanted Dean to do.

So, very slowly, Dean undressed him. Meeting every inch of newly uncovered skin with his lips, Castiel was grabbing handfuls of the blanket in pleasure by the time Dean got him down to just a neat pair of plain white boxers. He might not have made a noise, but his body language and eyes told Dean that Castiel would be moaning breathlessly if he vocalized, just like him. It was good to know, and seeing Castiel’s enjoyment only aroused Dean further.

Castiel turned, gently pushing Dean down onto the pillow as he came up to rest on his side, beginning to give him the same worshipful treatment that Dean had just lavished on him. Dean’s pleasure was audible, and Castiel had only just managed to work Dean’s sweatpants off past his ankles before Dean’s hand came forward, cupping gentle-but-keen at Castiel’s solidly tented underwear.

Castiel leaned over Dean then, his mouth dropping slightly open as he braced himself on the mattress and rubbed himself forward into Dean’s hand. A long, stuttering breath fell from his lips. Dean was left to imagine the loud moan that would have come with it. Dean found he didn’t miss it; Castiel was loud in other ways.

Like the way he was rocking against Dean’s hip, losing his lips and teeth in the sensitive skin at the base of Dean’s neck. Dean squirmed in delight underneath him. Sliding a hand down Castiel’s back and under the elastic into his boxers, Dean grabbed a firm handful of Castiel’s ass.

“Cas,” he rumbled against the alien’s ear, “I want you…”

Whether Castiel understood the words or not, the tone and the way Dean’s hips bucked back against his own spoke for themselves.

Dean raised his hips, and Castiel slid his boxers down. As Dean kicked them off the edge of the bed, Castiel briefly stood, shameless as he dropped his own underwear at the side of the bed.

Castiel’s cock bobbed thick and red out in front of him as he looked down at Dean, watching him settle back onto the bed. His eyes roamed painstakingly slowly up Dean’s body. When their eyes finally met, Dean realized from the alien’s lip-bitten expression that Castiel had one hand wrapped firmly around the base of his cock, curling his balls into his fingers, as the other hand fisted firmly at the head, just squeezing, interrupted with the occasional long stroke.

“Fuck,” the curse dropped deep from Dean’s lips, completely unbidden, as he watched Castiel pleasure himself at just the sight of him. Castiel seemed to take Dean’s exclamation as an invitation, however. He continued what was now steady, firm pumping at himself as he eased back down to the bed, over Dean.

Spreading his legs apart to admit Castiel in between, Dean reached down to take himself in hand. He could feel heat rising in his abdomen already, just from the amazing kisses, touches, and closeness they were sharing.

Castiel dipped down further, returning to Dean’s lips as their hands knocked together, their jerking increasing in pace as Dean’s pulse rocketed.

Castiel leaned more weight onto the arm that was supporting him near Dean’s head, and his near frantic pulling at his cock stopped. For a moment, Dean wondered what the alien was doing, until he felt a finger ghosting softly down across his ass. Blue eyes found his, questioning, silently seeking permission.

Any hesitation Dean may have had was chased away by the caution in Castiel’s eyes. This huge, fantastical creature could probably, Dean theorized, take whatever he wanted from Dean if he was so inclined. But Castiel wasn’t like that. He was caring, and he wanted Dean to want him in return.

“Please,” Dean breathed, nodding.

The finger that circled Dean’s tight muscle was slippery, awash with some kind of lubrication. Dean blinked. Castiel certainly hadn’t moved over to the nightstand where Dean had some stashed. His surprise must have carried across, because Castiel gave him an almost secret little smile.

Thinking back to the tentacles, Dean’s eyes widened slightly. _Oh. That’s not my lube,_ he thought suddenly. _It’s his… actually his._

Seeing his reaction, Castiel paused. He stilled completely, looking down at Dean with concern. He seemed worried that he’d freaked him out, his brow drawing together in unease.

“No, no—” Dean smiled, deciding to illustrate his point by pushing himself back against Castiel’s waiting fingers. “It’s fine, Cas. It’s actually, uh…” Dean flushed but continued, “It’s kinda hot, actually.”

Responding to Dean’s pushing, Castiel slid his finger in past the initial resistance of the tight ring of muscle at his entrance. He wasn’t exactly working Dean open expertly, but Dean had plenty of experience doing this to himself and didn’t sense any discomfort ahead.

Dean wondered briefly where Castiel had learned these human ways, before catching a brief glimpse of the dark TV screen over Castiel’s shoulder. _Oh right… I showed him how to browse around online._ Suppressing a giggle at what links his NASA-monitored internet history now probably contained, Dean moved to capture Castiel in another kiss.

Reaching down between them, Dean caught Castiel’s hand. “I’m good, Cas,” he breathed against his lips. “I’m ready. As long as you are,” he added.

Castiel seemed to understand, pulling himself back just a little to line them up. The hand that wasn’t supporting him on the mattress came up to Dean’s cheek. Dean expected it to be sticky with whatever strange, alien goo Castiel had used to lube him up, but it was dry, the fluid gone as quickly as it appeared.

For a moment, they were poised right on the precipice. Dean could feel the blunt warmth of Castiel’s erection pressing at his ass, but he didn’t slide home yet. Instead, they looked at each other, their eyes communicating more than words could have, even if they’d had the option. Castiel’s gaze was soft and happy. Dean searched his thoughts for a word to label it with, but all he could provide was _loving._ Castiel looked at him like he was the universe, and Dean knew his own expression mirrored it.

 _I fell in love with an alien,_ Dean thought helplessly as Castiel moved forward, filling him slowly. Dean groaned and gasped, shuddering around him as they fully connected. He couldn’t help but push back, meeting every snap forward that Castiel made.

Castiel radiated heat, and Dean’s thoughts fell into whiteness quickly as their thrusts picked up. Somehow, despite the raw power of his hips slapping forward into Dean, every motion Castiel made felt less and less like lust, and more like worship.

They didn’t last long. Dean watched the alien come undone above him, falling into Dean’s chest as his arms failed. He felt Cas sputtering out thick and dirty into him, painting his insides with deep thrusts that claimed him as his own. Dean followed him over the peak almost immediately.

They lay tangled for a long time, trading lazy kisses and soft glances, before Dean rose to get a cloth and some more coffee.

It was going to be a good day, he thought.


	11. Penumbra

The dust storm that blew in around Ares Base was severe, putting Dean and Castiel on lockdown for several days. Luckily, Dean was so far ahead with his workload that it didn’t really matter. It worked out well, as it meant he and Castiel got three full days to enjoy the new developments in their relationship.

Once they had taken the first step, everything was fairly easy, Dean discovered. Castiel didn’t leave the base any more. Each evening they spent together, watching the distant sun set from the observation room or learning every inch of each other in Dean’s—their—bed. When they fully woke (quite often after a repeat performance of the night before), they shared coffee and caught up on tasks around the base. Afternoons were Dean’s favorite, spent snuggling up on the couch in the entertainment room, working through all the movies Dean thought were most important. Castiel was delighted by Star Wars but somewhat skeptical of Indiana Jones. He thought 1980s’ horror movies were hilarious, silently grinning and shaking with mirth through the terrible special effects.

The afternoon of the third day, they lay on the couch, tangled together familiarly, Castiel’s arm slung over Dean’s chest as they spread out horizontally on their sides. It was easy for Dean to turn his head and look up at Castiel, propped up on his elbow above him, and watch his reactions to the films playing out on screen.

Castiel was squinting skeptically at _House of Wax,_ watching the character of Wade get slowly turned into a wax dummy, when Dean rolled over to look up at him. Gazing at Castiel’s profile, Dean craned his neck and watched him for a moment, studying his intense gaze and slightly creased brow. He looked so suspicious that Dean let out a small giggle, before biting it back, not wanting to disturb his viewing.

 _I am so perfectly content right now,_ Dean realized. It was a pleasant feeling, one he hadn’t felt in years, if ever.

Reaching up, Dean hooked one finger gently around Castiel’s chin, pulling his face down a few inches so that he could press his lips into the alien’s neck. Dean made a content noise as Castiel turned his head, trailing kisses up his jaw so that he could smile into his cheek.

“It’s crazy how happy I am right now,” Dean confessed, his tone reflecting his disbelief.

Castiel pushed up just slightly on the couch arm so that he could look down at Dean, tangling his spare hand in Dean’s sandy hair and carding his fingers through it. He studied Dean’s face for a few seconds, his eyes roaming over his features as if mapping every one. When he was done, Castiel smiled broadly and leaned down to bump at Dean’s nose with his own. _I’m happy, too,_ he seemed to say.

Dean smiled into the nose boop, before pulling Castiel down into a proper, deep kiss. He didn’t pull back when they stopped, just holding them close together.

“I love you, Cas. I wish you could understand me,” Dean confessed, finding that he was more sad that he wouldn’t hear a response, than awkward about saying it so openly.

Castiel just watched him as he spoke, taking in the whole of Dean’s face and his expression just as much as the words. Slowly, a brilliant smile broke over the alien’s face, and he pulled Dean back across the bare inches between them, peppering his forehead and cheeks with kisses.

Dean laughed, a relieved sound. “Okay,” he rephrased. “Maybe you do understand me.”

Castiel nudged him with his shoulder that was buried in the couch, as if to say, _Of course I understand you, dummy._

After making out long enough that they missed the end of the movie, Dean told Castiel to pick the next one while he went to get some food from the galley. Castiel still didn’t eat, though he’d take a bite if prompted by Dean.

Dean took his break to heat up food, use the restroom and make Castiel a coffee. The alien was already deeply wrapped up in the next movie when Dean came back carrying his dinner and Castiel’s drink. He didn’t look very happy, though.

As Dean approached, he looked at the screen and saw that Castiel was a good chunk of the way into _E.T._ The sharp breath that caught in Dean’s throat made him choke audibly, and he reached out to try and take the remote from where it sat limply in Castiel’s hand.

Scowling, Castiel snatched it back, not looking at Dean at all, but fixed unerringly on the screen, watching as the extra-terrestrial in the movie was hunted relentlessly by everyone but his child saviors.

“Cas, we don’t need to watch this—” Dean protested, but he was already too late.

Castiel watched for a few more moments before his shoulders dropped slightly, and he held the remote out to Dean with an impassive expression. His eyes dropped away from the TV, and he brought his feet up onto the couch, hugging his knees.

“Cas?” Dean tried, gently.

Castiel didn’t move, so Dean stepped around in front of him, dropping to his knees on the floor. He felt guilty, even if he hadn’t done anything wrong.

“I’m sorry, Cas,” Dean began softly. “Not all humans are… like me.”

Castiel raised his eyes enough to watch Dean’s face as he talked, though of course, he said nothing.

Dean reached forward, grasping one of Castiel’s wrists and holding onto it, just maintaining contact as he spoke.

“Some humans probably wouldn’t treat you very nicely. That’s why I haven’t told NASA about you—when I speak with Benny, on the comms link?” Dean gestured up the hallway.

Castiel’s expression was blank, but he nodded.

“I don’t want them to hurt you, Cas. I want to protect you.”

Somewhere in the back of Dean’s mind, a tiny voice reminded him, _Dude’s ten feet tall with tentacles, wings and, like, psychic dream powers and some shit. He can most definitely take care of himself._

Nonetheless, it seemed that Castiel appreciated his comment, as he moved one hand over to Dean’s stretched out arm, squeezing it and forcing out a small smile.

“I worry that—” Dean wasn’t sure how to phrase it, so he bumbled on. “I worry about what’s going to happen when I go back to Earth, Cas.”

It was something Dean hadn’t mentioned at all in his weeks here, because he honestly wasn’t really looking forward to it. Of course, he missed Sam, and Gabriel, and wanted to meet Jack. He missed Bobby, and his apartment, and decent food. But there was no Castiel there.

Mentioning the word “Earth” now seemed to throw a giant shadow over them.

“I can’t stay here with you. The scientists that come after me—I need you to understand that if you approach them, it might—” Dean’s voice cracked a little. “—It might not turn out as well as it did with me.”

Castiel’s brow creased. He tilted his head at Dean, and then flicked his finger back and forth between the two of them, before gesturing to the exterior window, pointing at the stars.

 _Oh God._ Dean’s heart broke.

“Cas, you—you can’t come with me.”

The words hung between them heavily for a moment, before Dean tried to continue.

“Ares 1, it’s only built for one person. I can’t stay here, but I can’t take you with me, either,” Dean explained, averting his eyes from Castiel so that he could blink them frantically. The words tasted like ash on his tongue, and he was afraid to look and see Castiel’s expression. “We talked about this, remember, before we—”

Dean couldn’t finish. _Before we knew we’d fallen in love and everything was different,_ he couldn’t say.

He felt Castiel trembling slightly beneath his hands.

When Dean finally looked up, he only caught the smallest glimpse of Castiel’s tear-streaked face before he disappeared, tumbling Dean forward onto the couch alone.

 

~~***~~

 

The alarm clock buzzing on Dean’s nightstand was vicious and uncaring. He reached out and flapped at it with a scowl, before covering his head with the pillow. It took him nearly an hour to persuade himself to get out of bed.

He made two coffees, out of habit, but eventually threw the second into the recycler when it grew cold.

Dean checked in with Mission Control, and of course, had to endure Naomi’s company. She berated him for shirking on his exercise requirements recently and insisted that he surface walk that afternoon to check for exterior dust storm damage.

They talked about his homing procedure, to begin the day after next, and he answered her questions with a strange, disconnected feeling. His lips formed words he couldn’t remember thinking, and somehow, he made it through the discussion.

At some point, when they were talking, Dean realized that he hadn’t been alone on Mars like this since his first day here. Every day since their first encounter, Castiel had arrived at Ares Base within an hour or two of Dean waking. More recently, he hadn’t even left. Dean didn’t even know how to look for him, he realized.

Once he was done with Naomi, Dean dragged himself around the basic Ares Base routines before he considered lunch. Having no appetite at all, he moved slowly toward the changing room, and lowered himself down onto the convenient bench to begin to pull on his space suit. He was so lost in thought, his legs and one arm in the suit, that he didn’t hear anyone enter the room.

Castiel stepped up in front of Dean, his sensible shoes and dark navy suit pants in view as Dean gazed at the floor. His sudden appearance made Dean jump, but his expression was nothing but relief when he looked up.

“Cas! You came back!”

Castiel nodded, a tiny sad smile ghosting through his face before disappearing completely.

“Cas,” Dean babbled, “you have to know I don’t want that—if I could stay, if there was any way I could take you to Earth then—”

Castiel silenced him with a finger to Dean’s lips, nodding slowly. He understood.

“Are you okay?” Dean looked up at Castiel, taking him in. The alien seemed… less solid, than usual. “Is something wrong?” he asked carefully, looking around Castiel’s face with concern.

Castiel gave him a scathing look, as if to say, _Of course I’m not alright, you ass._

Realizing, Dean huffed out a sad laugh. “Right, yeah. Of course. I just meant…” he reached forward, gently grasping Castiel’s arm.

It didn’t even feel right. Dean was holding an arm that was clad in several layers of business clothes; Castiel still dressed, at any point when he wasn’t in their bed, like a knock-off John Constantine, one you’d find in a comic from a cheap Chinese mall-vendor. But what he felt under his fingers was softer, fleshier; totally out of sync with what was in front of him.

Dean frowned in confusion, searching Castiel’s face until the alien finally looked him in the eye.

“What’s wrong, Cas?” Dean gestured up and down Castiel’s body. “Why are you having trouble with—this,” he gestured again, “today?”

Castiel looked almost embarrassed, but he pulled his arm from Dean’s light grasp so that he could tap two fingers to the side of his head, looking apologetic.

“It’s… in your head?” Dean guessed.

Castiel tilted his head and wrinkled his nose, as if to say, _Well, almost. Try again._

“It’s...mental?” Dean tried once more. “How you do this… change your body to this. It’s a mental thing.”

Castiel nodded simply.

“So, today you’re…” Dean trailed off. “Oh. You can’t focus today?”

Another simple nod, though with more regret.

“Oh, Cas,” Dean remarked sadly, reaching for his arm again. “You can’t hold this body, this—” Dean struggled to find an adequate word, “this _vessel_ that you use, because you’re upset? Because of me?”

Castiel shook his head, stepping just a fraction more toward Dean as he gestured between the two of them, his fixed, sad smile weakening a bit. _Because of us,_ he corrected.

Dean was glad that the alien didn’t seem to blame him, but the confirmation that the discussion had hurt Castiel, even though that had been clear from the start, made Dean’s heart sink further.

“I’m sorry,” Dean whispered, his eyes dropping.

Castiel reached across to pull at Dean’s jaw so that he looked up again from the bench where he still sat, partly in his space suit, encouraging Dean to look at him. He rubbed his thumb along Dean’s jawline; though out of the corner of Dean’s eye the appendage seemed to lengthen and darken, much like a trick of the light, only Dean knew better.

“Cas,” he murmured quietly, catching his gaze more firmly, “you know you don’t have to do that, right?” Dean reached up to press a hand to Castiel’s chest, tapping at it with his splayed fingers. “If you’re doing this for me?” He motioned up and down Castiel’s body with his other hand, covered in the space suit, just to clarify. “Then you don’t have to, Cas. Remember the night after you kissed me in the galley? When I searched for you, to kiss you back?”

Castiel nodded cautiously.

“I still kissed you, remember. Even though you didn’t look like some guy I almost covered in pie back on Earth,” Dean reminded him. “So, don’t worry about me. I told you I love you, right? That doesn’t mean only when you look a certain way.”

Dean smiled, standing from the bench and opening his arms, offering Castiel space within them.

The alien came willingly, wrapping his arms around Dean and resting his cheek onto Dean’s shoulder. They stood for a few minutes, each thawing the coldness they’d felt since the day before with the warmth of the other.

“I’m so sorry, Cas. I’m going to miss you so much,” Dean whispered into the top of Castiel’s messy, wild hair.

The kiss Castiel reached up to give him in response was long and carried enough emotion to replace all of Castiel’s words.

When Dean opened his eyes, the face before him was jet black, and the gaze that met his came from giant azure orbs that were watching his every reaction. Dean knew he was searching for fear, disgust or mistrust. So, he was determined to show Castiel none of those things.

Instead, Dean reached forward, his tongue diving deeply into Castiel’s mouth. Breathing shakily against the alien, Dean only held him closer.

Before Dean began to pull away to judge Castiel’s expression (hard to do, on the very alien face he now had), Dean felt a touch to his cheek. Looking down, he saw one of the thick tentacles he had seen in his dream caressing him. Dean leaned into it, returning his eyes fearlessly up to Castiel.

Dean felt a faint breeze as the black wings that towered above him shifted, barely fitting into the room and brushing on the ceiling above. The motion caused Castiel’s unique, clean and ozoney scent to waft around him. Dean idly thought that he smelled like the top of a mountain.

There was still an air of sadness between them, but as they stood and kissed, the feeling evolved into something tinged with desperation. They had so little time left.

As their lips crashed together more frantically, Dean felt a sharp thrill of excitement running through him.

“Cas,” he gasped between kisses, “Cas—please, will you…” Dean almost trailed off, but then realized it was silly to be embarrassed given the situation. “Will you touch me? With your tentacles, please?’

Castiel tilted his head to the side, dark and blue and mesmerizingly different, as if trying to judge why on earth Dean would ask such a thing.

“I want you to,” Dean gasped with their lips still dragging. “I’ve always had this, uh—well, it’s a fantasy, of mine. If you’re okay with it, I’d like— _Ahh!”_   

Castiel definitely understood, as evidenced by the thick tentacle thrusting down into the back of Dean’s space suit. The appendages seemed to be highly mobile and surprisingly delicate, when they wanted to be. Probing slowly at Dean’s clothing, Castiel raised the grey t-shirt that Dean was wearing beneath the suit and slid provocatively down into the back of his sweatpants.

Very swiftly, Dean was rock hard in his boxers, his heart rate accelerating. “Holy shit,” he gasped. “You feel…”

Dean trailed off, lost in the sensation of the damp yet velvety tentacle teasing across his ass cheek. The feeling of the suckers on the underside beginning to kiss their way across his skin completely overwhelmed him.

Castiel came forward to kiss Dean again, and Dean groaned into it.

“Amazing, it feels amazing,” he clarified against Castiel’s lips.

The tentacle that had up until this point been resting at Dean’s cheek, caressing it gently, shifted slightly to the side to admit a friend to Dean’s front. The third tentacle slid across his neck, sucking erotically at the skin at the nape, leaving little red sucker marks in its wake.

The movements were all simultaneous, all around Dean, and it was mesmerizing. His breath fell from his lips in hiccups that turned into soft, rhythmic moans as the appendage at the back began to slide down his ass crack. The one at his neck was apparently done giving him hickeys, and glided down his chest to disappear into the space suit at the front.

Dean felt it slide into his sweatpants, dancing over his cock through the fabric of his underwear.

“Oh god,” Dean moaned into Castiel’s mouth, the desperation that drove them keeping their lips connected even as Dean writhed with delight under Castiel’s ministrations.

The back tentacle, now oozing with some kind of self-produced lubrication, breached Dean at the exact same moment as the front one pushed aside his underwear, looping itself around the head of Dean’s already dripping cock and sliding down in a spiral to encompass the entire length.

“Fuck! Cas!” Dean screamed out at the sudden intrusion, his shout echoing around Ares Base without care.

Between his fluttering eyelids Dean saw Castiel’s ebony features contort into what could only be described as a gleeful smirk, and a whole new pair of tentacles came up to wrap around Dean’s back. Castiel held Dean tight with those two, cradling Dean close to his chest and lifting him slightly off the floor, supporting his weight.

Dean turned his head to press his cheek into Castiel’s sternum, moaning loudly as the tentacle that was probing his burning, stretched ass gave an experimental wiggle.

“Yes, fuck, please—” Dean was shameless, melting bonelessly into Castiel’s chest as he begged. “More, please,” he whined.

Castiel’s own breath was coming in gasps, though Dean wasn’t very sure how this was doing anything for him, or how he even derived pleasure in this form. He thought to ask, but the words were driven from his mouth with a shout as the limb that was wrapped around his dick in an oozing spiral _pulsed_ , squeezing him tight along the whole shaft before it began slipping up and down, rotating and sliding around him in a twist, perfectly in sync with the up and down movement.

Dean’s cock wept and quivered helplessly, his words reduced to little more than a pathetic keening noise.

 

The pair of tentacles that hugged Dean to Castiel’s chest lifted him back up, pressing him into Castiel’s searing hot lips. The kiss was pure desperation, swallowing Dean’s yells as the tentacle in his ass flicked firmly at his prostate, over and over.

The space suit began to slip down, and another tentacle came from somewhere to tug it off, giving all of the other appendages easier access as they worked Dean from every angle.

The gentle, caressing tentacle at Dean’s cheek took the place of Castiel’s tongue as the alien pulled back from their kiss, forcing ecstatic gurgling noises out of Dean. Castiel’s extremely long tongue travelled instead to his neck, licking and biting at the already red, sucker-marked skin.

Dean couldn’t remember any sexual experience that had been so overwhelming.

“Deeper,” he choked around the tentacle teasing his tongue. “So close, Cas… fuck me as deep as you can…” he begged. “I need you,” Dean cried, tears falling from his eyes as he was simply unable to contain the _everything_ that he was feeling, from every angle. “I don’t wanna go, Cas…”

The words only seemed to pull more from the alien as his limbs pumped and sucked and teased at every hole and sensitive spot Dean had.

When Dean came, suddenly, he could feel the tentacle around his cock milking his orgasm from him, a carefully placed sucker at his slit slurping and drawing out every last drop.

Trembling and moaning helplessly, Dean fell against Castiel’s chest, everything around him white and black and perfect.

Dean wasn’t sure if he passed out, or if Castiel held him so long that he fell into an exhausted sleep.

When Dean awoke, the sun was setting. Castiel lay in the dormitory bed beside him, human-looking again. He was watching Dean sleep.

Dean noticed that he was clean and clothed, and while not certain what Castiel had done to achieve that, never mind get him to the bed without him knowing, Dean was grateful.

He rolled forward, pressing his lips to Castiel’s forehead.

Castiel’s eyes fluttered shut as Dean murmured softly into his skin.

“I’ll never forget you, Cas.”

Castiel’s only response was to tuck his arms around Dean and pull him in closer.


	12. Escape Velocity

NASA had extremely advanced weather technology, to the point where Dean wasn’t certain exactly how it worked, and he trusted it explicitly. He often wondered why no one seemed to be able to ever get the weather right on Earth, but on Mars they had such an excellent track record. Naomi had informed Dean that everything was looking optimal for his departure, and of course she was completely correct. The sol dawned with low winds and barely a disruption to the weak sunlight that glistened overhead.

“Mission Control, this is Ares Base, do you copy?” Dean leaned his weight on the back of the comms chair, rather than sitting in it. He wasn’t in the best mood and hadn’t been doing well with sitting still.

“Ares Base, you’re coming in clear,” Benny sounded delighted. “Excellent day for retrieving our Martian, huh.”

Dean blinked. _Oh… me._

“Ha, yeah, Benny. Looks like the weather is fine for launch. So, I guess the next time we speak, I’ll be back in Ares 1,” Dean tried his best to sound upbeat.

It wasn’t easy though, with Castiel standing slightly behind him, waiting for him to be done.

“That’s right, brother,” Benny agreed. “If you’re ready, I’ll sign you out of the airlock in thirty minutes and put the base into shutdown, since Bartholomew, Zac and Michael won’t land for another week.”

“Yeah, that’s a good call, Benny,” Dean agreed. “I’ll head on out and catch you in the craft. Out.”

“Take care on the sand buddy. Out.”

Hitting the comms disconnection button in the base for the last time, Dean took a moment to look around the desk. He really would miss this place; not just Castiel, but the whole of Ares Base. It’d been his life for the past two months, and fantastical things had happened to him here.

Castiel’s arms slid slowly around his waist and pulled him in tight, his chin hooking over Dean’s shoulder from behind. His eyes were big and sad.

Dean leaned his head against Castiel’s, forcing up a smile.

“Guess I need to get moving, huh,” he commented quietly, not moving at all.

They had spent the last couple of days constantly in each other’s presence, no longer discussing Dean’s departure but under an unspoken agreement that they would make the best of what they had. They’d binged on YouTube, and Dean had introduced Castiel to classic rock music, and discovered that Castiel was ticklish at the top of his inner thighs. Castiel had shown more of himself in his true form, letting Dean curiously investigate the fascinating tentacles and wings that made him so different. In a surprise move, Castiel had taken Dean’s breath away by somehow teleporting him from one end of the base to the other, with no warning. Dean had made a comment about not being able to poop for a week, and Castiel had found his reaction so amusing he’d done in three more times that day.

But now they couldn’t avoid that Dean had to leave.

“Hey Cas, will you still be able to come here, and use the base, even if Benny locks the doors?” Dean enquired, gesturing to the door even though Castiel’s understanding of language had come on in leaps and bounds, and he rarely needed to use his hands to get his point across any more.

Castiel nodded and gave a tiny little smirk. _Couldn’t keep me out if they tried,_ Dean understood.

Grasping at his lover’s hand, Dean quickly moved down toward the galley. On the table, Dean had perched a box. He pointed to it now.

“Well, then that’s for you,” Dean said, his smile crooked and a little awkward.

Castiel eased open the flap of the cardboard storage box curiously. His eyes widened, and he pointed to his chest.

“Yes,” Dean confirmed. “Yours.”

Dean had gathered up the last of the coffee that Ares Base had, carefully adjusted the Base inventory, and pulled them out of storage for Castiel. It wasn’t much, but Dean felt like it was all he could give him. Well, that and one more thing.

Dean reached into the corner of the box to pull out a heavy black device, about the size of a book. He pressed a button on the top, where a tiny solar panel powered it. Dean knew that Castiel understood solar panels, so he didn’t bother to explain that part, merely turning on the screen.

“This is a mobile DSN connection,” Dean explained quietly, watching Castiel’s eyes roam over it. “It works kinda like a very basic GPS for planets.”

Castiel tilted his head to the side, the very same motion that he’d used to indicate his confusion since the very first day they’d met.

“Like a map of stars,” Dean pointed at some dots on the screen and spread his arms wide. “It’s silly, really. I just—” he paused, biting his lip.

Castiel nudged against his shoulder gently, encouraging him to talk.

“I just kinda thought that maybe, if you can ever leave Mars… maybe you can find me. Or like, if there are others, if you had a family…” he smiled half-heartedly. “It’s kind of a silly thought. But it’s all I—”

Castiel silenced Dean with a kiss, and they lost a few minutes to each other’s lips before they could pick up the conversation again. 

Drawing his thumb slowly across Castiel’s cheekbone, Dean sighed.

“I need to get into my suit and start the launch procedure at Ares 1—it’s robotic, but it takes hours.” Dean swallowed hard, not sounding at all convinced that he wanted to. “You know, the next mission that NASA have up here, I’m gonna be the very first to volunteer,” he added quietly.

Castiel nodded seriously, but Dean could see the hurt in the alien’s eyes just as it was in his.

_At least this isn’t one sided,_ Dean thought glumly. _At least when I fell in love with an alien, they loved me back._

It took Dean quite some time to get into his space suit, as Castiel kept stopping him for tearful kisses. Dean wasn’t much of a crier himself, but he couldn’t hold back the couple that did escape.

Eventually, he was ready other than putting his helmet on, and they were at the airlock.

Deans knuckles were white as he held the spherical helmet under his arm. He knew he needed to put it on, there was no putting off his departure, but he couldn’t move.

After a moment, Castiel leaned forward and took Dean’s face in both hands. He gave Dean a beautiful, sad smile before sweetly joining their lips one last time. Then, he gently tugged the helmet out from under Dean’s arm and put it on for him, locking it into place and flipping the clasps like he’d done it a hundred times.

The both pretended not to notice each other’s tears as they moved out onto the surface.

As Mars sped by while Dean rode Siona to his original landing site, Dean said goodbye to the strange, alien landscape. The sand and rocks in all the shades of sunset, the constant wind gusts and ever-shifting dunes had become so familiar to him, he knew it was going to be strange to spend the next two months in transit without them.

Dean was dreading the many empty days it would take him to get home.

Back on Earth, he’d have his family, his work at the propulsion lab once he was cleared to leave quarantine, things to distract him. But in space, flying home, he’d have nothing. Just memories of Castiel and an empty cabin with only one chair.

The preparations went too quickly for Dean’s taste.

Ares 1 was a new-tech rocket and was outfitted with blades that spun out from the sides, dislodging the piled-up sand that had accumulated around the rocket over the past few weeks. Castiel had carried Dean’s personal bag for him, and he placed it almost reverentially in the hold while Dean went to check in with Benny. The craft’s silent computers whirred to life, and Dean was forced to begin the countdown to craft pressurization.

Castiel gazed curiously around the cargo hold, nearly empty now as the dune bike was to be left here for the scientists. They were already on their way, only a week out from the planet. Most of what else had filled the space had been used. The rest of Ares One was exactly as Dean had left it; not a bad space considering its purpose, if a little cramped.   

Dean pulled Castiel into a tight hug.

“You need to get a safe distance from the rocket, Cas,” Dean explained. “It’s going to get really, really hot out there when the first stage ignites to get me out of the atmosphere,” Dean was gesturing around and pointing out parts of the rocket, which he had already taught Castiel all of the names for.

The alien seemed fascinated with it, curiously examining everything he could get close to.  Now, he nodded solemnly, and reached to pull Dean into one last, ferociously tight hug, tentacles and all.

Dean ruffled one gloved hand through Castiel’s hair.

“I love you, Cas. I’m going to miss you forever.”

Castiel nodded very solemnly.

 

~~***~~

 

Whenever a rocket launched from Earth, there were hundreds of people involved. Ground crews, backup teams, fire marshals, paramedics, emergency engineers, navigators, weathermen. Hundreds. On Mars, there was just Dean. Dean, and some very sophisticated AI that he was placing all his faith in. That was why Dean’s job was so high-risk, here; why Bobby always said he was willing to do things for the advancement of mankind that other people just wouldn’t.

Whether Bobby was right, or Dean just didn’t always think things through, was still in question.

Regardless, Dean tightened his harness in the lone cockpit seat of Ares 1 and considered that no matter what the reason, it was possible he was insane.

His heart hammered in his chest.

“Mission Control, this is Ares 1. Do you copy?” Dean began.

Usually, launch was Dean’s favorite part of a mission. Like a super powered roller coaster into the unknown, sitting in the cockpit and shooting helplessly up gave Dean a thrill. But he didn’t want to leave Mars.

That, coupled with the fact that this was the most dangerous launch he’d ever taken part in—an entirely solo launch on an alien planet—left Dean feeling melancholy and numb.

“Ares 1, this is Mission Control. We have you clear,” came Naomi’s firm voice. She sounded a little snappy, but Dean had worked with Naomi enough to know that was because she too was nervous. “All systems are initializing. Wind speed at a low 19 km p/h, no immediate dust clouds. Initial sand extraction successful. We’re ready to proceed to staging whenever you hit the switch, Dean.”

Dean looked out of the wide cockpit windows, his eyes searching the horizon for a tan trench coat, but Castiel was gone.

“Loud and clear, Naomi,” he responded professionally, “Begin final countdown if you please, Houston.”

_Stow your feelings and do your damn job, Dean,_ he thought viciously. _Pay attention. You’ve never been in the business of crashing and burning._

“Understood, Ares 1. Launch in T-10 minutes and counting.”

Dean watched every monitor, pinning his gaze on the readouts in front of him so he didn’t have to think about anything else.

“T-5 minutes and counting. Staring auxiliary power units. Arm devices.”

Once Dean had flicked his required switches and triple checked every reading, he leaned his head back in his seat.

“Ares 1, this is Mission Control. You are clear. Main engine start. Good luck, Dean.”

Dean could hear cheering in the background as the ground control room cheered him on. His knuckles were white, and his stomach churned.

The minutes dragged.

“Ares 1, we have solid rocket booster ignition.”

The whole craft vibrated, and Dean squeezed his eyes tight shut for a second until he felt the familiar sensation of the planet dropping away beneath him.

“Lift off confirmed!” Dean’s voice was thin; lift off was an achievement, but only half the battle in this case.

“Report velocity,” Naomi barked.

“8.7 km/s and climbing,” Dean managed.

“Hold.”

“10.0 km/s and climbing,” Dean continued, long-drilled habits overtaking despite his fear.

“Hold.”

“11.2 km/s, Houston. Escape velocity achieved!” Dean yelled, unable to move his head or hands, but celebrating internally that he’d got this far.

The cheering that erupted across the communication frequency was near deafening inside Dean’s suit.

“Escape velocity recorded. Congratulations, Dean. She’s all yours. Enjoy the ride.”

_Goodbye, Cas,_ was all Dean could think.


	13. Epilogue: Home Planet

  
**4 Months Later**

 

“Bean!” Jack screeched at the top of his lungs, his arms flailing wildly as Dean spun the skinny four-year-old up above his head.

“Dean!” Sam exclaimed in unison, hovering like the perfect helicopter parent.

Gabriel sat on the floor building a tower of blocks.

It was a quiet Sunday afternoon, and Sam and Gabriel had come over to Dean’s apartment for dinner.

Dean hadn’t made anything fancy; baked ziti, salad for Sam, and a cherry pie for desert that Gabriel spent the best part of ten minutes trying to guess the ingredient combination for. (Dean tricked him with the tapioca starch and almond extract.)

They’d eaten until they were only fit to roll, and now they lazed on Dean’s couch playing with Jack and chatting about how work had been that week. It was their usual weekend routine.

“Not only did he drop the pie plate,” Gabriel continued his story about his young apprentice Alfie, heedless of the screaming interruption, “but he dropped it right into the pastry case!”

Sam grimaced, “I didn’t know that part. No wonder you brought home so many pie slices.”

“Yeah,” Gabriel sighed. “Couldn’t sell them after they’d been on the floor. Knew Dean’d still wolf them down, though.”

“Wait, _what?_ ” Dean objected over Jack’s giggles. “You gave me foot pie? When?”

“When I dropped that box off at your lab on Thursday,” Gabriel grinned shamelessly.

“You asshole,” Dean complained. “I even let my boss have one of those. Anna deserves better.”

“Asshole!” chirped Jack happily.

“Dean!” Sam exclaimed, again. “Watch your mouth around Jack, please.”

Chuckling, Dean and Jack exchanged a secret look.

“Alright, family,” Gabriel pushed up off the floor and stood, cracking his back as he stretched up high. “As Dean failed to kill us with food—though commendable effort, Dean-o—we should probably be heading home. Some of us baker types have to be up at three in the morning.”

“Whose fault is that?” Dean grumbled. “No one made you choose a career in sugar.”

“Anyone would think you weren’t dying to kick us out,” Sam grinned, beginning to chase down Jack so that he could wrestle him into his coat.

“I could use your company a little more often, honestly,” Dean confessed. “But I’ll survive, for the sake of the bakery.”

Sam’s brow creased at Dean’s comment, and he herded Jack in Gabriel’s direction. Grabbing a couple of empty pie plates, he shoved one at Dean and tilted his head in the direction of the kitchen.

Dean obediently followed, moving up to the sink to begin to rinse his plate. “What’s up?” he asked, knowing that Sam had something to say.

“How’re you doing?” Sam asked quietly.

“Fine.”

“Liar,” Sam rolled his eyes. “It’s okay to not be okay, you know. Gabriel thinks that—”

“Wait,” Dean hissed, interrupting as he turned around to look at Sam, his hands still in the sink. “You didn’t tell him, did you?”

“No, Dean,” Sam glared a little. “But he can tell you’ve been off since you came back. Just like I could. If what you said is true, then—”

“If?” Dean snapped, frowning. “I didn’t tell you so that you could be a bitch about it, Sam. If you hadn’t made me I wouldn’t have said anything.”

Sam moved up to Dean’s side, sliding the plate he held into the sink. He sighed, crossing his arms across his chest.

“I know, Dean. I’m sorry,” he replied after a moment. “It’s a little hard to believe. Aliens and stuff. But what do I know? I haven’t seen the stuff you have. I think it has to be true, to be affecting you this much.”

Sam reached across, squeezing at Dean’s shoulder as Dean scrubbed the plates far more than was necessary.

“It’s been four months since you left Mars, Dean. Maybe you should, I dunno, sign up for a dating website or something.”

“No.”

“Dean—”

“I said _no_ , Sam,” Dean yelled, punctuating his sudden anger by thumping the heel of his hand against the edge of the sink. “I know what you think. I know you think I’m crazy. But you know what? I don’t care. I said I’m not ready for that kind of stuff, and honestly, I have no interest in it right now. I don’t want anybody because I _had_ somebody, okay? And I had to leave them behind. It wasn’t a choice, Sam,” Dean raged, spinning to glare at Sam’s quietly cowed face. “I don’t have to move on just because you say I should.”

Sam didn’t reply. He gave Dean a small, regretful smile and nodded, before reaching across to pull his brother into a rough hug.

“I’m sorry, Sammy,” Dean mumbled into Sam’s shoulder.

“Nah, I was a jerk,” Sam apologized, slapping at Dean’s back before he pulled away. “I’m sorry. Really. I guess I…” Sam paused, shifting slightly, before shrugging and continuing. “I dunno if it’s weird to say, but I’m happy you found someone. Even if it was only for a while.”

Dean nodded, and turned his face away from Sam. “Yeah, me too.”

Sam politely didn’t mention the shake in Dean’s voice.

“Sam!” Gabriel called from the living room. “Your son is chewing Dean’s couch!”

“He’s your son too!” Sam hollered back with a laugh, reaching to squeeze Dean on the shoulder once more. “I better get going, Dean,” he said, quiet again. “But if you want to talk about it—about him—you know it’s okay, right? I’m not going to tell anyone.”

Dean gave his brother a grateful smile. “Thanks for not making fun of me too much, Sam,” he admitted. “I realize I sound like a nut job in a cornfield, saying he’s been probed by aliens.”

“Gross, Dean. I don’t wanna think about the probing,” Sam teased, heading out of the kitchen door.

“You should,” Dean insisted, following him out to the front door. “It was awesome—”

“Shut up!” Sam wailed, lifting Jack to give Dean a goodbye hug.

“Bye, Jack-Jack,” Dean grinned, squeezing the youngster.

“Bye-bye, Uncle Bean,” Jack said seriously, putting a hand on Dean’s cheek. “Be happy, Bean.”

Dean, Sam and Gabriel all stared at the little blonde boy, melting a little.

“Aww.” Gabriel grinned. “This kid, I swear. He’s so cute when he’s trying to avoid letting you know he left pie down the side of the couch cushions.”

They were all laughing by the time Dean closed the door behind them.

He moved slowly through his apartment, picking up stray plates and toys. He realized Jack had left his favorite blanket on the couch.

 _I’ll drop it by Sam’s office in the morning,_ Dean decided, hanging it on the hook next to his work coat to remind himself.

Taking the remaining plates off to the kitchen to rinse, Dean found himself staring listlessly out of the window above the sink.

He hadn’t lied to Sam, not exactly. He _was_ fine. He got through his day to day and enjoyed the time he spent with his little family. But to himself, he’d admit that he’d never felt the loneliness of his day to day life more sharply in his life.

He missed Cas, was the simple truth.

He’d already applied for the next mission to Mars that had engineering openings, even though he’d only been Earthbound again for a few weeks. But he’d been told by Naomi, in no uncertain terms, that he needed recovery time. There were rules, she said, ground time that had to be logged before he’d be authorized to go interplanetary again.

Dean let out a long sigh. Nothing seemed fair. It wasn’t just that he missed Cas, though that was the bulk of it. He also had to live daily with the fear that he’d turn on the news and hear of the scientists on Mars capturing an alien species. Or, worse, accept the fact that if something like that happened, he’d be almost guaranteed to never hear about it.

Finishing the dishes, Dean wandered back to the living room.

Grabbing his current bottle of Johnnie Walker from the high cabinet where it now lived, safe from grabby four-year-old hands, he poured himself a couple of stiff fingers and drifted toward the couch. He’d put on a movie, he figured, then head to bed.

He browsed for a few minutes, before deciding that, at least for now, watching movies alone was still a bit of a sore point.

He sat contemplating just going to bed early when there was a knock on the door.

“Be right there,” he called, stashing the glass of whiskey safely up high on the mantle; it must be Sam, come back for Jack’s blanket.

He pulled the adored, well-chewed comfort object off the hook near his coat, taking it to the door with him.

“Hey—” he began, holding up the blanket as he pulled the door wide.

Dean trailed off, blinking.

Before him, on the doorstep to his apartment, was six feet of blue eyes, messy hair and trench coat.

Castiel smiled almost shyly, his fingers knotted in front of his chest just as Dean had seen way back, when they first met. He looked nervous, as if he wasn’t even sure if he was welcome. As his eyes settled on Dean, though, a twinkle came over them, as if he was about to share a secret.

“Hello, Dean,” he said.

 

  
**~~THE END~~**

 

**Notes for the Chapter:**

> Thank you so much for reading!
> 
> If you enjoyed this space adventure, you might be interested to know that there is now a sequel: [ Earthly Desires.](https://archiveofourown.org/works/17718662/chapters/41801075) Hope to see you there!
> 
> Please do stop by and give me a follow and a hi [on tumblr](https://malmuses.tumblr.com/), too. I love interacting with you all!
> 
> I appreciate every kudos and comment, with all of my <3 
> 
> \- Mal :))


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